{"id":251,"date":"2025-04-02T08:39:26","date_gmt":"2025-04-02T08:39:26","guid":{"rendered":"https:\/\/photonics.ws.hosei.ac.jp\/wp\/?page_id=251"},"modified":"2026-04-13T02:16:22","modified_gmt":"2026-04-13T02:16:22","slug":"%e5%8e%9f%e8%91%97%e8%ab%96%e6%96%87","status":"publish","type":"page","link":"https:\/\/photonics.ws.hosei.ac.jp\/wp\/?page_id=251","title":{"rendered":"\u7814\u7a76\u696d\u7e3e \u539f\u8457\u8ad6\u6587"},"content":{"rendered":"\n
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  1. H. Nakano, T. Yanagimoto, K. Kunitake, T. Takashima, T. Fujisawa<\/strong>, K. Maeda, and M. Arai, and \u201cBroadband emission of photoluminescence from Type-II quantum wells applied to superluminescent diodes,\u201d Physica Status Solidi (a), vol. 223, e202500586, Jan. 2026, DOI: https:\/\/doi.org\/10.1002\/pssa.202500586<\/strong><\/a>.<\/li>\n\n\n\n
  2. T. Fujisawa<\/strong>, Y. Tsuji, T. Mitarai, Y. Sawada, T. Okimoto, T. Hiratani, K. Komatsu, H. Yagi, and N. Fujiwara, \u201cMosaic-based waveguide lenses designed by the adjoint method based on the finite-element scheme,\u201d Optics Express, vol. 34, no. 2, pp. 2047-2060, Jan. 2026, DOI: https:\/\/doi.org\/10.1364\/OE.584131.<\/li>\n\n\n\n
  3. F. He, T. Matsuzaki, A. Iguchi, Y. Tsuji, and T. Fujisawa<\/strong>, \u201cEfficient topology optimization of photonic devices using domain decomposition finite element method,\u201d IEEE Photonics Journal, vol. 18, no. 2, pp. 2200407, Apr. 2026, DOI: 10.1109\/JPHOT.2026.3655434.<\/li>\n\n\n\n
  4. Y. Sawada, T. Fujisawa<\/u><\/strong>, T. Mitarai, K. Komatsu, T. Okimoto, T. Hiratani, H. Yagi, and N. Fujiwara, \u201cUltrasmall Four-Channel Multiplexer Designed by Bayesian Direct Binary Search Method,\u201d IEEE Photonics Technology Letters, vol. 38, no. 11, pp. 703-706, June 2026, DOI: 10.1109\/LPT.2026.3663414.<\/li>\n<\/ol>\n<\/div><\/div>\n<\/div>\n\n\n\n
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    2025<\/span>
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    1. K. Maeda, T. Fujisawa<\/u><\/strong>, and M. Arai, \u201cExcitation Intensity and Temperature Dependence of Photoluminescence in Mid-Infrared Region for Lattice-matched InAs\/GaAsSb Superlattice Grown by Metalorganic Vapor Phase Epitaxy,\u201d Journal of Materials Science: Materials in Electronics, vol. 36, 122, Jan. 2025, DOI: https:\/\/doi.org\/10.1007\/s10854-024-14142-7<\/strong><\/a>.<\/li>\n\n\n\n
    2. T. Fujisawa<\/u><\/strong> and Y. Tsuji, \u201cHighly confined out-of-plane corner states in air-hole type topological photonic crystal fiber,\u201d Journal of Optical Society of America B, vol. 42, no. 2, pp. 243-250, Feb. 2025, DOI: https:\/\/doi.org\/10.1364\/JOSAB.544796.<\/li>\n\n\n\n
    3. T. Fujisawa<\/u><\/strong> and Y. Tsuji, \u201cBroadband multimode interference coupler based on SiN waveguide designed by adjoint method,\u201d Optics Letters, vol. 50, no. 16, pp. 4986-4989, Aug. 2025, DOI: https:\/\/doi.org\/10.1364\/OL.566860.<\/li>\n<\/ol>\n<\/div><\/div>\n<\/div>\n\n\n\n

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      1. K., Hombu, K. Hikita, T. Fujisawa<\/u><\/strong>, K. Maeda, and M. Arai, \u201c<\/a>Metalorganic Vapor-Phase Epitaxy Growth of Multilayer Stacked InAsSb\/InAsP Superlattices on GaAs and InAs Substrates,\u201d Physica Status Solidi (a), vol.221, pp. 2300824, Feb. 2024.<\/li>\n\n\n\n
      2. K. Nakamura, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cTunable O-band high-tolerance silicon mode multiplexer based on phase-mismatched asymmetric directional couplers,\u201d Journal of the Optical Society of America B, vol. 41, no. 5, pp. 1106-1115, May 2024, DOI: https:\/\/doi.org\/10.1364\/JOSAB.515894<\/strong><\/a>.<\/li>\n<\/ol>\n<\/div><\/div>\n<\/div>\n\n\n\n

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        2023\u4ee5\u524d<\/span>
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        1. \u85e4\u6fa4\u525b<\/u><\/strong>, \u5c0f\u67f4\u6b63\u5247, \u201c3\u6b21\u5143\u975e\u7dda\u5f62\u5149\u5c0e\u6ce2\u8def\u306e\u305f\u3081\u306e\u30d5\u30eb\u30d9\u30af\u30c8\u30eb\u6709\u9650\u8981\u7d20\u30d3\u30fc\u30e0\u4f1d\u642c\u6cd5,\u201d \u96fb\u5b50\u60c5\u5831\u901a\u4fe1\u5b66\u4f1a\u8ad6\u6587\u8a8c, vol. J85-C, no. 6, pp. 440-448, June 2002.<\/li>\n\n\n\n
        2. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cFull-vector finite-element beam propagation method for three-dimensional nonlinear optical waveguides,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 20, no. 10, pp. 1876-1884, Oct. 2002.<\/li>\n\n\n\n
        3. \u85e4\u6fa4\u525b<\/u><\/strong>, \u5c0f\u67f4\u6b63\u5247, \u201c\u975e\u7dda\u5f62\u30d5\u30a9\u30c8\u30cb\u30c3\u30af\u7d50\u6676\u30d5\u30a1\u30a4\u30d0\u306e\u6ce2\u9577\u5206\u6563\u7279\u6027,\u201d \u96fb\u5b50\u60c5\u5831\u901a\u4fe1\u5b66\u4f1a\u8ad6\u6587\u8a8c, vol. J86-C, no. 1, pp. 72-73, Jan. 2003.<\/li>\n\n\n\n
        4. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cFinite element characterization of chromatic dispersion in nonlinear holey fibers,\u201d Optics Express, vol. 11, no. 13, pp. 1481-1489 June 2003.<\/li>\n\n\n\n
        5. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cA frequency-domain finite element method for modeling of nonlinear optical waveguide discontinuities,\u201d IEEE Photonics Technology Letters, vol. 16, no. 1, pp. 129-131, Jan. 2004, DOI: 10.1109\/LPT.2003.818924<\/a><\/strong>..<\/li>\n\n\n\n
        6. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cTime-domain beam propagation method for nonlinear optical propagation analysis and its application to photonic crystal circuits,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 22, no. 2, pp. 684-691, Feb. 2004.<\/li>\n\n\n\n
        7. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cFinite-element mode-solver for nonlinear periodic optical waveguides and its application to photonic crystal circuits,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 23, no. 1, pp. 382-387, Jan. 2005.<\/li>\n\n\n\n
        8. \u5c0f\u677e\u5b8f\u4e00, \u85e4\u6fa4\u525b<\/u><\/strong>, \u5c0f\u67f4\u6b63\u5247, \u201c\u30c1\u30e3\u30cd\u30eb\u963b\u6b62\u578b\u30d5\u30a9\u30c8\u30cb\u30c3\u30af\u7d50\u6676\u65b9\u5411\u6027\u7d50\u5408\u5668\u3092\u7528\u3044\u305f\u5149\u53cc\u5b89\u5b9a\u7d20\u5b50\u306e\u30b9\u30a4\u30c3\u30c1\u30f3\u30b0\u7279\u6027,\u201d \u96fb\u5b50\u60c5\u5831\u901a\u4fe1\u5b66\u4f1a\u8ad6\u6587\u8a8c, vol. J88-C, no. 9, pp. 716-723, Sept. 2005.<\/li>\n\n\n\n
        9. S.K. Varshney, T. Fujisawa<\/u><\/strong>, K. Saitoh, and M. Koshiba, \u201cNovel design of inherently gain-flattened discrete highly nonlinear photonic crystal fiber Raman amplifier and dispersion compensation using a single pump in C-band,\u201d Optics Express, vol. 13, no. 11, pp. 9516-9526, Nov. 2005.<\/li>\n\n\n\n
        10. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cFinite-element modeling of nonlinear Mach-Zehnder interferometers based on photonic crystal waveguides for all-optical signal processing,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.24, no. 1, pp.617-623, Jan. 2006.<\/li>\n\n\n\n
        11. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cPolarization-independent optical directional coupler based on slot waveguides,\u201d Optics Letters, vol. 31, no. 1, pp. 56-58, Jan. 2006.<\/li>\n\n\n\n
        12. T. Fujisawa<\/u><\/strong>, K. Saitoh, K. Wada, and M. Koshiba, \u201cChromatic dispersion profile optimization of dual-concentric-core photonic crystal fibers for broadband dispersion compensation,\u201d Optics Express, vol. 14, no. 2, pp. 893-900, Jan. 2006.<\/li>\n\n\n\n
        13. K. Morikawa, T. Fujisawa<\/u><\/strong>, K. Saitoh, and M. Koshiba, \u201cTransmission characteristics of laterally illuminated photonic crystal fibers,\u201d IEICE Electronics Express, vol. 3, no. 4, pp. 70-73, Feb. 2006.<\/li>\n\n\n\n
        14. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cAll-optical logic gates based on nonlinear slot waveguide couplers,\u201d Journal of Optical Society of America B, vol. 23, no. 4, pp. 684-691, Apr. 2006.<\/li>\n\n\n\n
        15. S.K. Varshney, T. Fujisawa<\/u><\/strong>, K. Saitoh, and M. Koshiba, \u201cDesign and analysis of a broadband dispersion compensating photonic crystal fiber Raman amplifier operating in S-band,\u201d Optics Express, vol. 14, no. 8, pp. 3528-3540, Apr. 2006.<\/li>\n\n\n\n
        16. N. Yokoi, T. Fujisawa<\/u><\/strong>, K. Saitoh, and M. Koshiba, \u201cApodized photonic crystal waveguide gratings,\u201d Optics Express, vol. 14, no. 10. pp. 4459-4468, May 2006.<\/li>\n\n\n\n
        17. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cTheoretical investigation of ultrasmall polarization-insensitive 1\u00b42 multi-mode interference waveguides based on sandwiched structures,\u201d IEEE Photonics Technology Letters, vol. 18, no. 11, pp. 1246-1248, June 2006.<\/li>\n\n\n\n
        18. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cAnalysis of photonic crystal waveguide gratings using coupled-mode theory and finite-element method,\u201d Applied Optics, vol. 45, no. 17, pp. 4114-4121, June 2006.<\/li>\n\n\n\n
        19. T. Fujisawa<\/u><\/strong> and M. Koshiba, \u201cGuided modes of nonlinear slot waveguides,\u201d IEEE Photonics Technology Letters, vol. 18, no. 14, pp. 1530-1532, July 2006.<\/li>\n\n\n\n
        20. K. Saitoh, T. Fujisawa<\/u><\/strong>, T. Kirihara, and M. Koshiba, \u201cApproximate empirical relations for nonlinear photonic crystal fibers,\u201d Optics Express, vol. 14, no. 14, pp. 6572-6582, July 2006.<\/li>\n\n\n\n
        21. K. Kakihara, N. Kono, K. Saitoh, T. Fujisawa<\/u><\/strong>, and M. Koshiba, \u201cImpact of structural deformations on polarization conversion in high index contrast waveguides,\u201d Optics Express, vol. 14, no. 16, pp. 7046-7056, Aug. 2006.<\/li>\n\n\n\n
        22. \u6850\u539f\u8a89\u4eba, \u85e4\u6fa4\u525b<\/u><\/strong>, \u9f4a\u85e4\u664b\u8056, \u5c0f\u67f4\u6b63\u5247, \u201c\u975e\u7dda\u5f62\u30d5\u30a9\u30c8\u30cb\u30c3\u30af\u7d50\u6676\u30d5\u30a1\u30a4\u30d0\u306e\u89e3\u6790\u7684\u8fd1\u4f3c\u7406\u8ad6,\u201d \u96fb\u5b50\u60c5\u5831\u901a\u4fe1\u5b66\u4f1a\u8ad6\u6587\u8a8c, vol. J89-C, no. 10, pp. 692-699, Oct. 2006.<\/li>\n\n\n\n
        23. \u77f3\u5ddd\u5609\u6a39, \u9f4a\u85e4\u664b\u8056, \u85e4\u6fa4\u525b<\/u><\/strong>, \u5c0f\u67f4\u6b63\u5247, \u201c\u7a7a\u9699\u3092\u6709\u3059\u308b\u30ea\u30c3\u30b8\u578b\u64ec\u4f3c\u4f4d\u76f8\u6574\u5408\u7b2c\u4e8c\u9ad8\u8abf\u6ce2\u767a\u751f\u7d20\u5b50\u306e\u6f0f\u308c\u640d\u5931\u8a55\u4fa1,\u201d \u96fb\u5b50\u60c5\u5831\u901a\u4fe1\u5b66\u4f1a\u8ad6\u6587\u8a8c, vol. J89-C, no. 10, pp. 700-707, Oct. 2006.<\/li>\n\n\n\n
        24. S.K. Varshney, N.J. Florous, K. Saitoh, M. Koshiba, and T. Fujisawa<\/u><\/strong>, \u201cNumerical investigation and optimization of a photonic crystal fiber for simultaneous dispersion compensation over S+C+L wavelength bands,\u201d Optics Communications, vol. 274, no. 1, pp. 74-79, June 2007.<\/li>\n\n\n\n
        25. T. Fujisawa<\/u><\/strong>, M. Arai, T. Kakitsuka, T. Yamanaka, Y. Kondo, and H. Yasaka, \u201cEnhanced temperature characteristics of InGaAs\/InAlGaAs multi-quantum-well lasers on low-In-content InGaAs ternary substrates,\u201d Applied Physics Express, vol. 1, no. 4, pp. 041203, Apr. 2008.<\/li>\n\n\n\n
        26. T. Sato, M. Mitsuhara, N. Nunoya, T. Fujisawa<\/u><\/strong>, K. Kasaya, F. Kano, and Y. Kondo, \u201c2.33-mm-wavelength distributed feedback lasers with InAs-In0.53<\/sub>Ga0.47<\/sub>As multiple-quantum wells on InP substrates,\u201d IEEE Photonics Technology Letters, vol. 20, no. 12, pp. 1045-1047, June 2008.<\/li>\n\n\n\n
        27. (Invited paper) T. Sato, M. Mitsuhara, T. Kakitsuka, T. Fujisawa<\/u><\/strong>, and Y. Kondo, \u201cMetalorganic vapor phase epitaxial growth of InAs\/InGaAs multiple quantum well structures on InP substrates,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol. 14, no. 4, pp.992-997, July\/August 2008.<\/li>\n\n\n\n
        28. M. Arai, T. Fujisawa<\/u><\/strong>, W. Kobayashi, K. Nakashima, M. Yuda, and Y. Kondo, \u201cHigh-temperature operation of 1.26 mm Fabry-Perot laser with InGaAs metamorphic buffer on GaAs substrate,\u201d IEE Electronics Letters, vol. 44, no. 23, pp. 1359-1360, Nov. 2008.<\/li>\n\n\n\n
        29. M. Arai, W. Kobayashi, T. Fujisawa<\/u><\/strong>, M. Yuda, T. Tadokoro, K. Kinoshita, S. Yoda, and Y. Kondo, \u201c10-Gbps direct modulation using a 1.31-mm ridge waveguide laser on an InGaAs ternary substrates,\u201d Applied Physics Express, vol. 2, no. 1, pp. 022101, Jan. 2009.<\/li>\n\n\n\n
        30. M. Arai, T. Tadokoro, T. Fujisawa<\/u><\/strong>, W. Kobayashi, K. Nakashima, M. Yuda, and Y. Kondo, \u201cUncooled (25-85\u00b0C) 10 Gbit\/s operation of 1.3 mm-range metamorphic Fabry-Perot laser on GaAs substrates,\u201d IEE Electronics Letters, vol. 45, no. 7, pp. 359-360, Mar. 2009.<\/li>\n\n\n\n
        31. M. Arai, K. Nakashima, T. Fujisawa<\/u><\/strong>, T. Tadokoro, W. Kobayashi, M. Yuda, and Y. Kondo, \u201cHigh-temperature operation of 1.26-mm ridge waveguide laser with InGaAs metamorphic buffer on GaAs substrate,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol. 15, no. 3, pp.724-730, May\/June 2009.<\/li>\n\n\n\n
        32. T. Fujisawa<\/u><\/strong>, M. Arai, T. Yamanaka, Y. Kondo, and F. Kano, \u201cMicroscopic design of GaInNAs quantum well laser diodes on ternary substrates for high-speed and high-temperature operations,\u201d Journal of Applied Physics, vol. 105, no. 11, pp. 113114, June 2009.<\/li>\n\n\n\n
        33. W. Kobayashi, M. Arai, T. Yamanaka, N. Fujiwara, T. Fujisawa<\/u><\/strong>, M. Ishikawa, K. Tsuzuki, Y. Shibata, Y. Kondo, and F. Kano, \u201cWide temperature range (-25\u00b0C to 100\u00b0C) operation of a 10-Gbit\/s, 1.55-mm electroabsorption modulator integrated DFB laser for 80-km SMF transmission,\u201d IEEE Photonics Technology Letters, vol.21, no. 15, pp.1054-1056, Aug. 2009.<\/li>\n\n\n\n
        34. T. Fujisawa<\/u><\/strong>, M. Arai, N. Fujiwara, W. Kobayashi, T. Tadokoro, K. Tsuzuki, Y. Akage, R. Iga, T. Yamanaka, and F. Kano, \u201c25-Gbit\/s 1.3-mm InGaAlAs-based electroabsorption modulator integrated with a DFB laser for metro-area (40 km) 100-Gbit\/s Ethernet system,\u201d IET Electronics Letters, vol.45, no. 17, pp.900-901, Aug. 2009.<\/li>\n\n\n\n
        35. W. Kobayashi, T. Yamanaka, M. Arai, N. Fujiwara, T. Fujisawa<\/u><\/strong>, K. Tsuzuki, T. Ito, T. Tadokoro, and F. Kano, \u201cWide temperature range operation of a 1.55 mm 40-Gb\/s electroabsorption modulator integrated DFB laser for very short reach applications,\u201d IEEE Photonics Technology Letters, vol.21, no. 18, pp.1317-1319, Sep. 2009.<\/li>\n\n\n\n
        36. M. Arai, T. Tadokoro, T. Fujisawa<\/u><\/strong>, W. Kobayashi, K. Nakashima, M. Yuda, and Y. Kondo, \u201c10-Gb\/s direct modulation up to 100\u00b0C using 1.3-mm-range metamorphically grown strain compensated InGaAs-GaAs MQW laser on GaAs substrate,\u201d IEEE Photonics Technology Letters, vol.21, no. 18, pp.1344-1346, Sep. 2009.<\/li>\n\n\n\n
        37. T. Fujisawa<\/u><\/strong>, T. Sato, M. Mitsuhara, T. Kakitsuka, T. Yamanaka, Y. Kondo, and F. Kano, \u201cSuccessful application of the 8-band k<\/em><\/strong>\u2219p<\/em><\/strong> theory to optical properties of highly strained In(Ga)As\/InGaAs quantum wells with strong conduction-valence band coupling,\u201d IEEE Journal of Quantum Electronics, vol. 45, no. 9, pp.1183-1191, Sep. 2009.<\/li>\n\n\n\n
        38. W. Kobayashi, M. Arai, T. Yamanaka, N. Fujiwara, T. Fujisawa<\/u><\/strong>, T. Tadokoro, K. Tsuzuki, Y. Kondo, and F. Kano, \u201cDesign and fabrication of 10-\/40-Gbit\/s, uncooled electroabsorption modulator integrated DFB laser with butt-joint structure,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 28, no. 1, pp.164-171, Jan. 2010.<\/li>\n\n\n\n
        39. T. Fujisawa<\/u><\/strong>, M. Arai, and F. Kano, \u201cMany-body design of highly strained GaInNAs electroabsorption modulators on GaInAs ternary substrates,\u201d Journal of Applied Physics, vol. 107, pp. 093107, May 2010.<\/li>\n\n\n\n
        40. W. Kobayashi, N. Fujiwara, T. Yamanaka, T. Tadokoro, T. Fujisawa<\/u><\/strong>, Y. Shibata, M. Ishikawa, K. Tsuzuki, and F. Kano, \u201cFull C-band 10-Gb\/s 40-km SMF transmission of InGaAlAs electroabsorption modulator,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 28, no. 20, pp.3012-3018, Oct. 2010.<\/li>\n\n\n\n
        41. T. Fujisawa<\/u><\/strong>, T. Yamanaka, T. Tadokoro, N. Fujiwara, M. Arai, W. Kobayashi, Y. Kawaguchi, K. Tsuzuki, and F. Kano, \u201cTheoretical and experimental investigations of the incident-power-dependent extinction ratio of electroabsorption modulator integrated with DFB laser,\u201d IEEE Journal of Quantum Electronics, vol. 47, no. 1, pp.60-65, Jan. 2011.<\/li>\n\n\n\n
        42. T. Fujisawa<\/u><\/strong>, S. Kanazawa, H. Ishii, N. Nunoya, Y. Kawaguchi, A. Ohki, N. Fujiwara, K. Takahata, R. Iga, F. Kano, and H. Oohashi, \u201c1.3-mm, 4\u00d725-Gbit\/s, monolithically integrated light source for metro area 100-Gbit\/s Ethernet,\u201d IEEE Photonics Technology Letters, vol. 23, no. 6, pp.356-358, Mar. 2011.<\/li>\n\n\n\n
        43. T. Fujisawa<\/u><\/strong>, K. Takahata, W. Kobayashi, T. Tadokoro, N. Fujiwara, S. Kanazawa, and F. Kano, \u201c1.3-mm, 50-Gbit\/s electroabsorption modulators integrated with a DFB laser for beyond 100G parallel LAN applications,\u201d IET Electronics Letters, vol. 47, no. 12, pp.709-710, June 2011.<\/li>\n\n\n\n
        44. T. Fujisawa<\/u><\/strong>, K. Takahata, T. Tadokoro, W. Kobayashi, A. Ohki, N. Fujiwara, S. Kanazawa, T. Yamanaka, and F. Kano, \u201cLong-reach 100Gbit Ethernet light source based on 4\u00d725-Gbit\/s 1.3-mm InGaAlAs EADFB lasers,\u201d IEICE Transactions on Electronics, vol. E94-C, no. 7, pp.1167-1172, July 2011.<\/li>\n\n\n\n
        45. (Invited paper) W. Kobayashi, K. Tsuzuki, T. Tadokoro, T. Fujisawa<\/u><\/strong>, N. Fujiwara, T. Yamanaka, and F. Kano, \u201c40-Gb\/s operation of 1.3\/1.55-mm InGaAlAs electroabsorption modulator integrated with DFB laser in compact TO-CAN package,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol. 17, no. 5, pp.1183-1190, Oct. 2011.<\/li>\n\n\n\n
        46. (Invited paper) S. Kanazawa, T. Fujisawa<\/u><\/strong>, A. Ohki, H. Ishii, N. Nunoya, Y. Kawaguchi, N. Fujiwara, K. Takahata, R. Iga, F. Kano, and H. Oohashi, \u201cA compact EADFB laser array module for a future 100-Gbit\/s Ethernet transceiver,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol. 17, no. 5, pp.1191-1197, Oct. 2011.<\/li>\n\n\n\n
        47. T. Fujisawa<\/u><\/strong>, T. Kitoh, K. Watanabe, K. Suzuki, M. Kotoku, and H. Takahashi, \u201cWide-bandwidth, low-waveguide-width-sensitivity InP-based multimode interference coupler designed by wavefront matching method,\u201d IEICE Electronics Express, vol.8, no.24, pp.2100-2105, Dec. 2011.<\/li>\n\n\n\n
        48. T. Fujisawa<\/u><\/strong>, S. Kanazawa, K. Takahata, W. Kobayashi, T. Tadokoro, H. Ishii, and F. Kano, \u201c1.3-mm, 4\u00d725G, EADFB laser array module with large-output-power and low-driving-voltage for energy-efficient 100GbE transmitter,\u201d Optics Express, vol.20, no. 1, pp.614-620, Jan. 2012.<\/li>\n\n\n\n
        49. T. Tadokoro, W. Kobayashi, T. Fujisawa<\/u><\/strong>, T. Yamanaka, and F. Kano, \u201c43-Gb\/s 1.3-mm DFB laser for 40-km transmission,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.30, no. 15, pp.2520-2524, Aug. 2012.<\/li>\n\n\n\n
        50. T. Fujisawa<\/u><\/strong>, T. Itoh, S. Kanazawa, K. Takahata, Y. Ueda, R. Iga, H. Sanjo, T. Yamanaka, M. Kotoku, and H. Ishii, \u201cUltracompact, 160-Gbit\/s transmitter optical subassembly based on 40-Gbit\/s\u00d74 monolithically integrated light source,\u201d Optics Express, vol.21, no. 1, pp.182-189, Jan. 2013.<\/li>\n\n\n\n
        51. T. Fujisawa<\/u><\/strong>, S. Kanazawa, W. Kobayashi, K. Takahata, A. Ohki, R. Iga, and H. Ishii, \u201c50-Gbit\/s uncooled operation (5~85\u00b0C) of 1.3-mm electroabsorption modulator integrated with a DFB laser,\u201d IET Electronics Letters, vol. 49, no. 3, pp.204-205, Jan. 2013.<\/li>\n\n\n\n
        52. S. Kanazawa, T. Fujisawa<\/u><\/strong>, N. Nunoya, A. Ohki, K. Takahata, H. Sanjoh, R. Iga, and H. Ishii, \u201cUltra-compact 100GbE transmitter optical sub-assembly for 40-km SMF transmission,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 31, no. 4, pp.602-608, Feb. 2013.<\/li>\n\n\n\n
        53. W. Kobayashi, T. Ito, <\/em>T. Yamanaka, T. Fujisawa<\/u><\/strong>, <\/em>Y. Shibata, T. Kurosaki, M. Kotoku, T. Tadokoro, and H. Sanjo,<\/em> \u201c50-Gb\/s direct modulation of 1.3-\u03bcm InGaAlAs-based DFB laser with ridge waveguide structure,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol.19, no.4, pp.1500908, July\/Aug. 2013.<\/li>\n\n\n\n
        54. T. Fujisawa<\/u><\/strong>, S. Kanazawa, Y. Ueda, W. Kobayashi, K. Takahata, A. Ohki, T. Itoh, M. Kotoku, and H. Ishii, \u201cLow-loss cascaded Mach-Zehnder multiplexer integrated 25-Gbit\/s\u00d74-lane EADFB laser array for future CFP4 100GbE transmitter,\u201d IEEE Journal of Quantum Electronics, vol.49, no.12, pp.1001-1007, Dec. 2013.<\/li>\n\n\n\n
        55. T. Ohyama, A. Ohki, K. Takahata, T. Itoh, N. Nunoya, T. Fujisawa<\/u><\/strong>, S. Kanazawa, R. Iga, and H. Sanjoh, \u201cCompact 100Gbit\/s Ethernet transmitter optical sub-assembly for 40-km transmission using polarization beam combiner,\u201d IEEE Photonics Technology Letters, vol.25, no.24, pp.2416-2418, Dec. 2013.<\/li>\n\n\n\n
        56. W. Kobayashi, T. Fujisawa<\/u><\/strong>, <\/em>K. Tsuzuki, Y. Ohiso, T. Itoh, S. Kanazawa, T. Yamanaka, and H. Sanjoh,<\/em> \u201cDesign and fabrication of wide wavelength range 25.8-Gb\/s, 1.3-mm, push-pull-driven DMLs,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.32, no.1, pp.3-9, Jan. 2014.<\/li>\n\n\n\n
        57. S. Kanazawa, T. Fujisawa<\/u><\/strong>, <\/em>N. Nunoya,A. Ohki, K. Takahata, H. Sanjoh, R. Iga, and H. Ishii,<\/em> \u201cCompact flip-chip interconnection 112-Gbit\/s EADFB laser array module with high eye-mask margin,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.32, no.1, pp.115-121, Jan. 2014.<\/li>\n\n\n\n
        58. W. Kobayashi, T. Fujisawa<\/u><\/strong>, S. Kanazawa, and H. Sanjoh, \u201c25 Gbaud\/s 4-PAM (50Gb\/s) modulation and 10-km SMF transmission with 1.3-mm InGaAlAs-based DML,\u201d IET Electronics Letters, vol.50, no.4, pp.299-300, Feb. 2014.<\/li>\n\n\n\n
        59. S. Kanazawa, T. Fujisawa<\/u><\/strong>, <\/em>A. Ohki, K. Takahata, H. Sanjoh, R. Iga, and H. Ishii,<\/em> \u201cCompact flip-chip interconnection 8\u00d750-Gb\/s EADFB laser array module for 400-Gb\/s transceiver,\u201d IET Electronics Letters, vol.50, no.7, pp.533-534, Mar. 2014.<\/li>\n\n\n\n
        60. Y Ueda, T. Fujisawa<\/u><\/strong>, <\/em>K. Takahata, M. Kohtoku, and H. Ishii,<\/em> \u201cInP-based compact transversal filter for monolithically integrated light source array,\u201d Optics Express, vol.22, no.7, pp.7844-7851, Apr. 2014.<\/a><\/li>\n\n\n\n
        61. W. Kobayashi, T. Fujisawa<\/u><\/strong>, T. Itoh, S. Kanazawa, Y. Ueda, and H. Sanjoh, \u201cAdvantage of EADFB laser for 25 Gbaud\/s 4-PAM (50Gb\/s) modulation and 10-km SMF transmission,\u201d IET Electronics Letters, vol.50, no.9, pp.683-685, Apr. 2014.<\/li>\n\n\n\n
        62. Y Ueda, T. Fujisawa<\/u><\/strong>, <\/em>S. Kanazawa, W. Kobayashi, K. Takahata, and H. Ishii,<\/em> \u201cVery-low-voltage operation of Mach-Zehnder interferometer-type electroabsorption modulator using asymmetric couplers,\u201d Optics Express, vol.22, no.12, pp.14610-14616, June 2014.<\/li>\n\n\n\n
        63. T. Sato, S. Makino, Y. Ishizaka, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cThree-dimensional finite-element mode-solver for nonlinear periodic optical waveguides and its application to photonic crystal waveguides,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.32, no.21, pp.3409-3417, Nov. 2014.<\/li>\n\n\n\n
        64. W. Kobayashi, M. Arai, T. Fujisawa<\/u><\/strong>, T. Sato, T. Itoh, K. Hasebe, S. Kanazawa, Y. Ueda, T. Yamanaka, and H. Sanjoh, \u201cNovel approach for chirp and output power compensation of 40-Gbit\/s EADFB laser by integrating short SOA,\u201d Optics Express, vol.23, no.7, pp.9533-9542, Apr. 2015, DOI: 10.1364\/OE.23.009533<\/a><\/em>.<\/li>\n\n\n\n
        65. T. Ohyama, A. Ohki, K. Takahata, T. Itoh, N. Nunoya, H. Mawatari, T. Fujisawa<\/u><\/strong>, S. Kanazawa, R. Iga, and H. Sanjoh, \u201cTransmitter optical sub-assembly using polarization beam combiner for 100Gbit\/s Ethernet over 40 km transmission,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.33, no.9, pp.1985-1992, May 2015.<\/li>\n\n\n\n
        66. T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cMaterial gain analysis of GeSn\/SiGeSn quantum wells for mid-infrared Si-based light sources based on many-body theory,\u201d IEEE Journal of Quantum Electronics, vol.51, no.5, pp.7100108, May 2015, DOI: 10.1109\/JQE.2015.2410283<\/a>.<\/strong><\/li>\n\n\n\n
        67. T. Sato, S. Makino, Y. Ishizaka, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cA rigorous definition of nonlinear parameter g and effective area Aeff<\/sub> for photonic crystal optical waveguides,\u201d Journal of Optical Society of America B, vol.32, no.6, pp.1245-1251, June 2015, DOI: 10.1364\/JOSAB.32.001245.<\/li>\n\n\n\n
        68. S. Kanazawa, T. Fujisawa<\/u><\/strong>, K. Takahata, T. Itoh, Y. Ueda, W. Kobayashi, H. Ishii, and H. Sanjoh, \u201cFlip-chip interconnection lumped-electrode EADFB laser for 100-Gb\/s\/l transmitter,\u201d IEEE Photonics Technology Letters, vol.27, no.16, pp.1699-1701, Aug. 2015, DOI: 10.1109\/LPT.2015.2438076.<\/li>\n\n\n\n
        69. S. Makino, T. Sato, Y. Ishizaka, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cThree-dimensional finite-element time-domain beam propagation method and its application to 1-D photonic crystal coupled resonator waveguide,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.33, no.18, pp.3836-3842, Sep. 2015, DOI: 10.1109\/JLT.2015.2446514.<\/li>\n\n\n\n
        70. W. Kobayashi, S. Kanazawa, Y. Ueda, T. Fujisawa<\/u><\/strong>, H. Sanjoh, and M. Itoh, \u201c4\u00d725 Gbit\/s (100 Gbit\/s) simultaneous operation of InGaAlAs based DML array monolithically integrated with MMI coupler,\u201d IET Electronics Letters, vol.51, no.19, pp.1516-1517, Sep. 2015, DOI: 10.1049\/el.2015.1476.<\/li>\n\n\n\n
        71. T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cQuantum-confined Stark effect analysis of GeSn\/SiGeSn quantum wells for mid-infrared Si-based electroabsorption devices based on many-body theory,\u201d IEEE Journal of Quantum Electronics, vol.51, no.11, pp.8400207, Nov. 2015, DOI: 10.1109\/JQE.2015.2488363.<\/li>\n\n\n\n
        72. S. Kanazawa, T. Fujisawa<\/u><\/strong>, H. Ishii, K. Takahata, Y. Ueda, R. Iga, and H. Sanjoh, \u201cHigh-speed (400 Gb\/s) 8-channel EADFB laser array module using flip-chip interconnection technique,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol.21, no.6, pp.1501106, Nov.\/Dec. 2015, DOI: 10.1109\/JSTQE.2015.2415197.<\/li>\n\n\n\n
        73. Y. Ueda, T. Fujisawa<\/u><\/strong>, <\/em>S. Kanazawa, W. Kobayashi, K. Takahata, H. Sanjoh, H. Ishii,<\/em> and M. Kohtoku, \u201cLow-driving-voltage operation of MZI-type EA modulator integrated with DFB laser using optical absorption and interferometric extinction,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol.21, no.6, pp.1501306, Nov.\/Dec. 2015, DOI: 10.1109\/JSTQE.2015.2420591.<\/li>\n\n\n\n
        74. S. Makino, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cEnhancement of optical nonlinearity in coupled resonator optical waveguide based on slotted 1-D photonic crystal cavity,\u201d IEEE Photonics Journal, vol.7, no.6, pp.4501608, Dec. 2015, DOI: 10.1109\/JPHOT.2015.2493729.<\/li>\n\n\n\n
        75. T. Sato, S. Makino, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cDesign of reflection-suppressed all-optical diode based on asymmetric L-shaped nonlinear photonic crystal cavity,\u201d Journal of Optical Society of America B, vol.33, no.1, pp.54-61, Jan. 2016, DOI: 10.1364\/JOSAB.33.000054.<\/li>\n\n\n\n
        76. (Invited paper) S. Kanazawa, T. Fujisawa<\/u><\/strong>, K. Takahata, Y. Ueda, H. Ishii, R. Iga, W. Kobayashi, and H. Sanjoh, \u201cFlip-chip interconnection technique for beyond 100-Gbit\/s EADFB laser array transmitter,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.34, no.2, pp.296-302, Jan. 2016, DOI: 10.1109\/JLT.2015.2462728.<\/li>\n\n\n\n
        77. T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cA group delay spread analysis of strongly coupled 3-core fibers: A effect of bending and twisting,\u201d Optics Express, vol.24, no.9, pp.9583-9591, May 2016, DOI: 10.1364\/OE.24.009583.<\/li>\n\n\n\n
        78. Y Ueda, T. Fujisawa<\/u><\/strong>,<\/em> and M. Kohtoku, \u201c8-channel Reflection-type Transversal Filter for Compact and Easy-to-Fabricate InP-based Optical Multiplexer,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.34, no.11, pp.2684-2691, June 2016, DOI: 10.1109\/JLT.2016.2541165.<\/li>\n\n\n\n
        79. S. Nishimoto, T. Fujisawa<\/u><\/strong>, Y. Sasaki, H. Uemura, and K. Saitoh, \u201cTheoretical investigation of 6 mode multi\/demultiplexer based on fused type multicore fiber coupler,\u201d IEEE Photonics Journal, vol.8, no.3, pp.7802908, June 2016, DOI: 10.1109\/JPHOT.2016.2559438<\/a><\/strong>.<\/li>\n\n\n\n
        80. S. Kanazawa, W. Kobayashi, Y. Ueda, T. Fujisawa<\/u><\/strong>, T. Ohno, T. Yoshimatsu, H. Ishii, and H. Sanjoh, \u201cLow-crosstalk operation of directly modulated DFB laser array TOSA for 112-Gbit\/s application,\u201d Optics Express, vol.24, no.12, pp.13555-13562, June 2016, DOI: 10.1364\/OE.24.013555.<\/li>\n\n\n\n
        81. S. Kanazawa, W. Kobayashi, Y. Ueda, T. Fujisawa<\/u><\/strong>, K. Takahata, T. Ohno, T. Yoshimatsu, H. Ishii, and H. Sanjoh, \u201c30-km error-free transmission of directly modulated DFB laser array transmitter optical sub-assembly for 100-Gbit\/s application,\u201d IEEE\/OSA Journal of Lightwave Technology, vol.34, no.11, pp.3646-3652, Aug. 2016, DOI: 10.1109\/JLT.2016.2520942.<\/li>\n\n\n\n
        82. Y. Ishizaka, M. Nagai, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cA photonic-plasmonic mode converter using mode-coupling-based polarization rotation for metal inserted silicon platform,\u201d IEICE Electronics Express, vol.14, no.2, pp.1-10, Jan. 2017, DOI: 10.1587\/elex.13.20160989.<\/li>\n\n\n\n
        83. (Invited paper) K. Saitoh, N. Hanzawa, T. Sakamoto, T. Fujisawa<\/u><\/strong>, Y. Yamashita, T. Matsui, K. Tsujikawa, and K. Nakajima, \u201cPLC-based mode multi\/demultiplexers for mode division multiplexing,\u201d Optical Fiber Technology, vol. 35, pp. 80-92, Feb. 2017, DOI: 10.1016\/j.yofte.2016.08.002<\/a><\/strong>.<\/li>\n\n\n\n
        84. Y. Ishizaka, S. Makino, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cA metal-assisted silicon slot waveguide for highly-sensitive gas detection,\u201d IEEE Photonics Journal, vol.9, no.1, pp. 6800609, Feb. 2017, DOI: 10.1109\/JPHOT.2016.2630308.<\/li>\n\n\n\n
        85. Y. Tobita, T. Fujisawa<\/u><\/strong>, T. Sakamoto, T. Matsui, S. Saitoh, K. Takenaga, K. Aikawa, S. Aozasa, K. Nakajima, and K. Saitoh, \u201cOptimal design of 4LP-mode multicore fibers for high spatial density,\u201d Optics Express, vol.25, no.5, pp. 5697-5709, Mar. 2017, DOI: 10.1364\/OE.25.005697.<\/li>\n\n\n\n
        86. T. Fujisawa<\/u><\/strong>, S. Makino, T. Sato, and K. Saitoh, \u201cLow-loss, compact, and fabrication-tolerant Si-wire 90\u00b0 waveguide bend using clothoid and normal curves for large scale photonic integrated circuits,\u201d Optics Express, vol.25, no.8, pp. 9150-9159, Apr. 2017, DOI: 10.1364\/OE.25.009150.<\/li>\n\n\n\n
        87. Y. Yamashita, T. Fujisawa<\/u><\/strong>, S. Makino, N. Hanzawa, T. Sakamoto, T. Matsui, K. Tsujikawa, F. Yamamoto, K. Nakajima, and K. Saitoh, \u201cDesign and fabrication of broadband PLC-based 2-mode multi\/demultiplexer using wavefront matching method,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 35, no. 11, pp. 2252-2258, June 2017, DOI: 10.1109\/JLT.2016.2641461.<\/li>\n\n\n\n
        88. T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cGroup delay spread analysis of coupled-multicore fibers: A comparison between weak and tight bending conditions,\u201d Optics Communications, vol.393, pp. 232-237, June 2017, DOI: 10.1016\/j.optcom.2017.02.064<\/a>.<\/strong><\/li>\n\n\n\n
        89. S. Makino, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cWavefront matching method based on full-vector finite-element beam propagation method for polarization control devices,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 35, no. 14, pp. 2840-2845, July 2017, DOI: <\/strong>10.1109\/JLT.2017.2700482<\/a>.<\/strong><\/li>\n\n\n\n
        90. T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cFull-vector finite-element beam propagation method for helicoidal waveguides and its application to twisted photonic crystal fiber,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 35, no. 14, pp. 2894-2901, July 2017, DOI: 10.1109\/JLT.2017.2703889<\/a>.<\/strong><\/li>\n\n\n\n
        91. Y. Yamashita, S. Makino, T. Fujisawa<\/u><\/strong>, N. Hanzawa, T. Sakamoto, T. Matsui, K. Tsujikawa, F. Yamamoto, K. Nakajima, and K. Saitoh, \u201cPLC-based LP11<\/sub> mode rotator with curved trench structure devised from WFM method,\u201d IEEE Photonics Technology Letters, vol. 29, no. 13, pp. 1063-1066, July 2017, DOI: 10.1109\/LPT.2017.2700496.<\/li>\n\n\n\n
        92. K. Saitoh, T. Fujisawa<\/u><\/strong>, and T. Sato, \u201cCoiling size dependence of group delay spread in coupled multicore fibers without intentional twisting,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 35, no. 20, pp. 4559-4566, Oct. 2017, DOI: 10.1109\/JLT.2017.2746756<\/a>.<\/strong><\/li>\n\n\n\n
        93. T. Fujisawa<\/u><\/strong>, Y. Amma, Y. Sasaki, S. Matsuo, K. Aikawa, K. Saitoh, and M. Koshiba, \u201cCrosstalk analysis of heterogeneous multicore fibers using coupled-mode theory,\u201d IEEE Photonics Journal, vol. 9, no.5, pp.7204108, Oct. 2017, DOI:10.1109\/JPHOT.2017.2749439.<\/li>\n\n\n\n
        94. T. Sato, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cDesign of high-forward-transmission all-optical diode based on cascaded side-coupled photonic crystal cavities,\u201d Journal of Optical Society of America B, vol. 34, no.12, pp.2493-2500, Dec. 2017 (selected as Editor\u2019s pick), DOI: 10.1364\/JOSAB.34.002493<\/a>.<\/li>\n\n\n\n
        95. T. Fujisawa<\/u><\/strong>, Y. Yamashita, T. Sakamoto, T. Matsui, K. Tsujikawa, K. Nakajima, and K. Saitoh, \u201cScrambling-type three-mode PLC multiplexer based on cascaded Y-branch waveguide with integrated mode rotator,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 36, no.10, pp.1985-1992, May 2018, DOI: 10.1109\/JLT.2018.2798619<\/a>.<\/strong><\/li>\n\n\n\n
        96. S. Ohta, T. Fujisawa<\/u><\/strong>, S. Makino, T. Sakamoto, T. Matsui, K. Tsujikawa, K. Nakajima, and K. Saitoh, \u201cSi-based Mach-Zehnder wavelength\/mode multi\/demultiplexer for a WDM\/MDM transmission system,\u201d Optics Express, vol.26, no.12, pp. 15211-15220, June 2018, DOI:<\/a> 10.1364\/OE.26.015211.<\/li>\n\n\n\n
        97. (Invited paper) E. Taguchi, T. Fujisawa<\/u><\/strong>, Y. Yamashita, S. Makino, N. Hanzawa, T. Sakamoto, T. Matsui, K. Tsujikawa, K. Nakajima, F. Yamamoto, and K. Saitoh, \u201cA review on PLC-based two-mode multi\/demultiplexer designed by wavefront matching method,\u201d IEICE Transactions on Electronics, vol. E101-C, no.7, pp. 518-526, July 2018, DOI: <\/a>10.1587\/transele.E101.C.518<\/a>.<\/strong><\/li>\n\n\n\n
        98. S. Nakano, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cBeam propagation analysis of optical activity and circular dichroism in helically twisted photonic crystal fiber,\u201d Japanese Journal of Applied Physics, vol. 57, pp. 08PF06 Aug. 2018, <\/a>DOI: 10.7567\/JJAP<\/em>.57.08PF06.<\/li>\n\n\n\n
        99. Y. Sawada, T. Sato, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cDevelopment of the wavefront matching method based on the 3-D finite-element method and its application to Si-wire mode converters,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 36, no.17, pp.3652-3659, Sept. 2018, <\/a>DOI: <\/strong>10.1109\/JLT.2018.2843383<\/a>.<\/li>\n\n\n\n
        100. T. Fujisawa<\/u><\/strong><\/a>, and K. Saitoh, \u201cOff-axis core transmission characteristics of helically twisted photonic crystal fibers,\u201d Optics Letters, vol. 43, no.20, pp.4935-4938, Oct. 2018, DOI: 10.1364\/OL.43.004935<\/a>.<\/strong><\/li>\n\n\n\n
        101. M. Akie, T. Fujisawa<\/u><\/strong>, T. Sato, M. Arai, and K. Saitoh, \u201cGeSn\/SiGeSn multiple-quantum-well electroabsorption modulator with taper coupler for mid-infrared Ge-on-Si platform,\u201d IEEE Journal of Selected Topics in Quantum Electronics, vol. 24, no. 6, pp.3400208, Nov.\/Dec. 2018, <\/a>DOI: <\/strong>10.1109\/JSTQE.2018.2827673<\/a>.<\/strong><\/li>\n\n\n\n
        102. T. Fujisawa<\/u><\/strong><\/a>, M. Arai, and K. Saitoh, \u201cMicroscopic gain analysis of modulation-doped GeSn\/SiGeSn quantum wells: Epitaxial design toward high-temperature lasing,\u201d Optics Express, vol. 27, no. 3, pp.2457-2464, Feb. 2019, DOI: 10.1364\/OE.27.002457<\/a>.<\/li>\n\n\n\n
        103. M. Kudo, S. Ohta, E. Taguchi, T. Fujisawa<\/u><\/strong>, T. Sakamoto, T. Matsui, K. Tsujikawa, K. Nakajima, and K. Saitoh, \u201cProposal of Mach-Zehnder mode\/wavelength multi\/demultiplexer based on Si\/Silica hybrid PLC platform,\u201d Optics Communications, vol.433, pp. 168-172, Feb. 2019, DOI: <\/strong><\/a>10.1016\/j.optcom.2018.10.004<\/a>.<\/strong><\/li>\n\n\n\n
        104. T. Sato, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cAll-optical diode suppressing broadband backward transmission using single- and four-port photonic crystal cavities,\u201d IEEE Photonics Journal, vol. 11, no.1, pp.4900214, Feb. 2019, <\/a>DOI: 10.1109\/JPHOT.2018.2888632.<\/li>\n\n\n\n
        105. Y. Sawada, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cCMOS-compatible Si-wire polarization beam splitter based on wavelength-insensitive coupler,\u201d IEICE Electronics Express, vol. 16, no.8, pp.1-6, Apr. 2019, DOI: 10.1587\/elex.16.20181126.<\/a><\/li>\n\n\n\n
        106. K. Yoshida, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cOptimum index profile of few-mode coupled multicore fibers for reducing the group delay spread,\u201d Optics Express, vol. 27, no. 11, pp.16281-16295, May 2019, DOI: <\/a>10.1364\/OE.27.016281<\/a>.<\/li>\n\n\n\n
        107. S. Nakano, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cThe effect of core offset on the mode converting characteristics in twisted single mode fibers,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 37, no. 21, pp. 5479-5485, Nov. 2019, <\/a>DOI: <\/strong>10.1109\/JLT.2019.2940692<\/a>.<\/strong><\/li>\n\n\n\n
        108. T. Fujisawa<\/u><\/strong><\/a>, J. Takano, Y. Sawada, T. Sakamoto, T. Matsui, K. Nakajima, and K. Saitoh, \u201cA novel Si four-wavelength multiplexer for 100\/400GbE using higher-order mode composed of (a)symmetric directional couplers and TE1<\/sub>-TM0<\/sub> mode converter,\u201d Optics Express, vol. 27, pp. 36286-36296, Dec. 2019, DOI: 10.1364\/OE.27.036286<\/a>.<\/li>\n\n\n\n
        109. M. Shirata, T. Fujisawa<\/u><\/strong>, T. Sakamoto, T. Matsui, K. Nakajima, and K. Saitoh, \u201cA design of small mode-dependent-loss scrambling-type mode (de)multiplexer based on PLC,\u201d Optics Express, vol. 28, pp. 9653-9665, Mar. 2020, DOI: <\/a>10.1364\/OE.387890<\/a>.<\/li>\n\n\n\n
        110. T. Fujisawa<\/u><\/strong><\/a> and K. Saitoh, \u201cGeometric-phase-induced arbitrary polarization and orbital angular momentum generation in helically twisted birefringent photonic crystal fiber,\u201d Photonics Research, vol. 8, no. 8, pp.1278-1288, Aug. 2020, DOI: 10.1364\/PRJ.393255<\/a>.<\/li>\n\n\n\n
        111. Y. Sawada, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cBroadband and compact silicon mode converter designed using a wavefront matching method,\u201d<\/a> Optics Express, vol. 28, no. 25, pp. 38196-38205, Dec. 2020, DOI: https:\/\/doi.org\/10.1364\/OE.411769<\/a>.<\/li>\n\n\n\n
        112. T. Fujisawa<\/u><\/strong><\/a>, J. Takano, Y. Sawada, and K. Saitoh, \u201cLow-loss and small 2 \u00d7 4\u03bb multiplexers based on 2 \u00d7 2 and 2 \u00d7 1 Mach-Zehnder interferometers with on-chip polarization multiplexing for 400GbE,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 39, no. 1, pp. 193-200, Jan. 2021, DOI: 10.1109\/JLT.2020.3025369<\/a>.<\/strong><\/li>\n\n\n\n
        113. K. Nakamura, T. Fujisawa<\/u><\/strong>, T. Sakamoto, T. Matsui, K. Nakajima, and K. Saitoh, \u201cTunable broadband mode dividers based on wavelength insensitive coupler using thermo-optic effect for flexible modal power adjustment in MDM network,\u201d Journal of the Optical Society of America B, vol. 38, no. 3, pp. 946-952, Mar. 2021, DOI: https:\/\/doi.org\/10.1364\/JOSAB.415499<\/a><\/strong>.<\/li>\n\n\n\n
        114. T. Fujisawa<\/u><\/strong> and K. Saitoh, \u201cBayesian direct-binary-search algorithm for the efficient design of mosaic-based power splitters,\u201d OSA Continuum, vol. 4, no. 4, pp.1258-1270, Apr. 2021, https:\/\/doi.org\/10.1364\/OSAC.422116.<\/li>\n\n\n\n
        115. K. Nakamura, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cHigh-tolerance CWDM4 wavelength multiplexer based on 2\u00d72\/2\u00d71 MZ filters with polarization multiplexing,\u201d IEICE Electronics Express, vol. 18, no. 8, pp. 20210110, Apr. 2021, DOI: 10.1587\/elex.18.20210110.<\/li>\n\n\n\n
        116. T. Fujisawa<\/u><\/strong>, T. Sakamoto, M. Miyata, T. Matsui, T. Hashimoto, R. Kasahara, T. Mori, R. Imada, K. Nakajima, and K. Saitoh, \u201cSix-mode scrambler based on cascaded side-wall grating waveguides,\u201d Japanese Journal of Applied Physics, vol. 60, pp. 062002, May 2021, DOI: https:\/\/doi.org\/10.35848\/1347-4065\/abfa31<\/a>.<\/strong><\/li>\n\n\n\n
        117. Y. Sawada, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cBroadband silicon four-mode multi\/demultiplexer designed by wavefront matching method,\u201d Optics Express, vol. 29, no. 17, pp. 27322-27331, Aug. 2021, DOI: https:\/\/doi.org\/10.1364\/OE.434178<\/a><\/strong>.<\/li>\n\n\n\n
        118. T. Fujisawa<\/u><\/strong> and K. Saitoh, \u201cArbitrary polarization and orbital angular momentum generation based on spontaneously broken degeneracy in helically twisted ring-core photonic crystal fiber,\u201d Optics Express, vol. 29, no. 20, pp. 31689-31705, Sep. 2021, DOI: https:\/\/doi.org\/10.1364\/OE.432401<\/a><\/strong>.<\/li>\n\n\n\n
        119. Y. Wang, T. Fujisawa<\/u><\/strong>, Y. Sagae, T. Sakamoto, T. Matsui, K. Nakajima, and K. Saitoh, \u201cA novel core allocation in heterogeneous step-index multi-core fibers with standard cladding diameter,\u201d IEEE\/OSA Journal of Lightwave Technology, vol. 39, no. 22, pp. 7231-7237, Nov. 2021, DOI: 10.1109\/JLT.2021.3112656.<\/strong><\/li>\n\n\n\n
        120. N. Sugawara, T. Fujisawa<\/u><\/strong>, K. Nakamura, Y. Sawada, T. Mori, T. Sakamoto, R. Imada, T. Matsui, K. Nakajima, and K. Saitoh, \u201cModal amplitude and phase estimation of multimode near field patterns based on artificial neural network with the help of grey-wolf-optimizer,\u201d Optical Fiber Technology, vol. 67, pp. 102720, Dec. 2021, DOI: https:\/\/doi.org\/10.1016\/j.yofte.2021.102720<\/a><\/strong>.<\/li>\n\n\n\n
        121. Y. Wang, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cAnalytical expression for mode-coupling coefficient between non-identical step-index cores and its application to multi-core fiber design within 125-\u03bcm cladding diameter,\u201d Optics Communications, vol. 506, pp. 127552, Mar. 2022, DOI: https:\/\/doi.org\/10.1016\/j.optcom.2021.127552<\/a>.<\/strong><\/li>\n\n\n\n
        122. T. Muratsubaki, T. Fujisawa<\/u><\/strong>, Y. Sawada, T. Sato, and K. Saitoh, \u201cDirect-binary-search algorithm for fabrication-tolerant photonic-crystal-like subwavelength structures and its application to a four-mode waveguide crossing in 2-\u03bcm waveband,\u201d Japanese Journal of Applied Physics, vol. 61, no. 4, pp. 042003, Apr. 2022, DOI: https:\/\/doi.org\/10.35848\/1347-4065\/ac54fc.<\/li>\n\n\n\n
        123. Y. Sawada, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cA novel algorithm of wavefront-matching method for stable and efficient design of Si waveguides,\u201d IEEE Photonics Technology Letters, vol. 34, no. 7, pp. 359-362, Apr. 2022, DOI: 10.1109\/LPT.2022.3159830<\/li>\n\n\n\n
        124. K. Nakamura, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cHybrid algorithm based on grey wolf optimizer and direct binary search for the efficient design of a mosaic-based device,\u201d Journal of the Optical Society of America B, vol. 39, no. 5, pp. 1329-1337, May 2022, DOI: https:\/\/doi.org\/10.1364\/JOSAB.451593<\/a>.<\/strong><\/li>\n\n\n\n
        125. Y. Sawada, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cComparison of scalar and vector WFM method through the design of high-D waveguide lenses,\u201d IEEE Photonics Technology Letters, vol. 34, no. 10, pp. 533-536, May 2022, DOI:10.1109\/LPT.2022.3170940.<\/li>\n\n\n\n
        126. T. Fujisawa<\/u><\/strong> and K. Saitoh, \u201cArbitrary higher-order optical spatial state generation by using spontaneously broken degeneracy modes in helically twisted ring-core hole assisted fibers,\u201d Optics Express, vol. 30, no. 14, pp. 24565-24578, July 2022, DOI: https:\/\/doi.org\/10.1364\/OE.463607<\/a>.<\/strong><\/li>\n\n\n\n
        127. T. Muratsubaki, T. Fujisawa<\/u><\/strong>, T. Sato, and K. Saitoh, \u201cProposal of mosaic-based 2\u00d72 3-dB couplers for prospective on-chip communication in mid-infrared wavelengths around 2.1 \u03bcm,\u201d Journal of the Optical Society of America B, vol. 39, no. 9, pp. 2522-2530, Sept. 2022, DOI:https:\/\/doi.org\/10.1364\/JOSAB.460644.<\/strong><\/li>\n\n\n\n
        128. H. Wang, T. Fujisawa<\/u><\/strong>, T. Sato, T. Mori, T. Sakamoto, Y. Yamashita, R. Imada, K. Nakajima, and K. Saitoh, \u201c6-Mode and 10-Mode photonic lantern mode multi\/demultiplexers based on silica planar lightwave circuit,\u201d Optics Communications, vol. 529, pp. 129098, Feb. 2023, DOI: https:\/\/doi.org\/10.1016\/j.optcom.2022.129098<\/a><\/strong>.<\/li>\n\n\n\n
        129. T. Sato, K. Homma, T. Fujisawa<\/u><\/strong>, Y. Sagae, T. Sakamoto, T. Matsui, K. Nakajima, and K. Saitoh, \u201cMode converter using bent and twisted coupled-multicore fibers for group delay spread reduction,\u201d Optical Fiber Technology, vol. 77, pp. 103286, May 2023, DOI: https:\/\/doi.org\/10.1016\/j.yofte.2023.103286<\/a>.<\/li>\n\n\n\n
        130. Z. Zhao, Y. Wang, T. Sato, T. Fujisawa<\/u><\/strong>, and K. Saitoh, \u201cInvestigation of heterogeneous step-index 2LP-mode multi-core fibers based on two-ring layout with standard cladding diameter,\u201d Optics Continuum, vol. 2, no. 5, pp. 1137-1147, May 2023, DOI: https:\/\/doi.org\/10.1364\/OPTCON.482118<\/a>.<\/strong><\/li>\n\n\n\n
        131. T. Sato, T. Fujisawa<\/u><\/strong>, M. Wada, T. Mori, T. Sakamoto, R. Imada, T. Matsui, K. Nakajima, and K. Saitoh, \u201cDesign of silica-PLC LP11<\/sub> mode rotator based on adiabatic mode conversion,\u201d Optics Express, vol. 31, no. 15, pp. 23910-23922, July 2023, DOI: https:\/\/doi.org\/10.1364\/OE.493501.<\/strong><\/li>\n\n\n\n
        132. T. Fujisawa<\/u><\/strong>, T. Mitarai, T. Okimoto, N. Kono, N. Fujiwara, T. Sato, H. Yagi, and K. Saitoh, \u201cBayesian design of mosaic-based mode multiplexers for various wavelength bands,\u201d Optics Express, vol. 31, no. 16, pp. 26842-26853, July 2023, DOI: https:\/\/doi.org\/10.1364\/OE.492673<\/strong><\/a>.<\/li>\n\n\n\n
        133. Z. Zhao, Y. Wang, T. Sato, T. Fujisawa<\/u><\/strong>, T. Iwaya, Y. Sagae, T. Sakamoto, T. Matsui, K. Nakajima, and K. Saitoh, \u201c<\/a>Investigation of double-cladding heterogeneous step-index 2LP-mode multi-core fiber with two-ring layout,\u201d Journal of the Optical Society of America B, accepted for publication.<\/strong><\/li>\n\n\n\n
        134. T. Fujisawa<\/u><\/strong>, T. Mitarai, Y. Sawada, T. Okimoto, N. Kono, N. Fujiwara, T. Muratsubaki, H. Yagi, \u201cUltrasmall power splitters with triangular lattice mosaic patterns designed by Bayesian DBS method,\u201d IEEE Photonics Technology Letters, vol. 35, no. 21, pp. 1139-1142, Nov. 2023, DOI: <\/a>https:\/\/doi.org\/10.1109\/LPT.2023.3306313<\/strong><\/a>.<\/li>\n\n\n\n
        135. T. Mori, T. Fujisawa<\/u><\/strong>, J. Sakamoto, Y. Yamashita, T. Sakamoto, R. Imada, R. Ima, T. Sato, K. Watanabe, R. Kasahara, T. Hashimoto, K. Saitoh, and K. Nakajima, \u201cVariable mode-dependent-loss equalizer based on silica-PLC for three-mode transmission,\u201d <\/a>Optical Fiber Technology, vol. 81, pp. 103547, Dec. 2023, DOI:https:\/\/doi.org\/10.1016\/j.yofte.2023.103547.<\/li>\n\n\n\n
        136. H. Wang, T. Fujisawa<\/u><\/strong>, T. Sato, M. Wada, T. Mori, T. Sakamoto, R. Imada, T. Matsui, K. Nakajima, and K. Saitoh, \u201cDesign of PLC E31<\/sub>-E13<\/sub> and E-LP tapered mode converters using fast quasiadiabatic dynamics,\u201d IEICE Electronics Express, vol. 20, no. 23, pp. 20230392, Dec. 2023, DOI:DOI: 10.1587\/elex.20.20230392.<\/li>\n<\/ol>\n<\/div><\/div>\n<\/div>\n
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