[2] L. G. Kazovsky, L. Curtis, W. C. Young et al.. All-fiber 90° optical hybrid for coherent communications[J]. Appl. Opt., 1987, 26(3): 437~439
[3] G. Kejian, W. Yizun. An improved all-fiber 90° optical hybrid[J]. Microwave and Opt. Technol. Lett., 1990, 3(4): 122~124
[4] J. Hankey, J. Urquhart, A. J. Moseley et al.. Balanced polarization diversity receiver using hybrid assembly techniques for optical coherent multichannel systems[J]. Electron. Lett.,1991, 27(21): 1935~1937
[5] W. R. Leeb. Optical 90°hybrid for Costas-type receivers[J]. Electron. Lett., 1990, 26(18): 1431~1432
[6] S. Norimatsu, N. Takachio, Y. Inoue et al.. An optical 90°-hybrid balanced receiver module using a planar lightwave circuit [J]. IEEE Photon. Technol. Lett., 1994, 6(6): 737~740
[7] H. Tsunetsugu, M. Hosoya, S. Norimatsu et al.. A packaging technique for an optical 90°-hybrid balanced receiver using a planar lightwave circuit[J]. IEEE Trans. on Components, Packaging, and Manufacturing Technology-Part B, 1996, 19(3): 569~574
[8] T. G. Hodgkinson, R. A. Harmon, D. W. Smith et al.. In-phase and quadrature detection using 90°optical hybrid receiver experiments and design considerations[J]. IEE Proceedings, 1988, 135(3): 260~267
[9] E. C. M. Pennings, Dolf Schouten et al.. Ultra fabrication-tolerant fully packaged micro-optical polarization diversity hybrid[J]. J. Lightwave Technology, 1995, 13(10): 1985~1991
[10] M. Seimetz, C. M. Weinert. Options, feasibility, and availability of 2×4 90° hybrids for coherent optical systems[J]. J. Lightwave Technology, 2006, 24(3): 1317~1322
[11] P. S. Cho, G. Harston, Ch. J. Kerr et al.. Improvement of coherent homodyne detection performance using time-gated amplification and LiNbO3 optical 90° hybrid [C]. SPIE, 2004, 5403: 762~773
[12] D. Hoffmann, H. Heidrich, G. Wenke et al.. Integrated optics eight-port 90° hybrid on LiNbO3[J]. J. Lightwave Technology, 1989, 7(5): 794~798
[13] E. C. M. Pennings, R. J. Deri, R. Bhat et al.. Ultracompact, all-passive optical 90°hybrid on InP using self-imaging[J]. IEEE Photon. Technol. Lett., 1993, 6(5): 701~703
[14] S. H. Jeong, K. Morito. Optical 90° hybrid with broad operating bandwidth of 94 nm[J]. Opt. Lett., 2009, 34(22): 3505~3507
[15] S. H. Jeong, K. Morito. Compact optical 90° hybrid employing a tapered 2×4 MMI coupler serially connected by a 2×2 MMI coupler[J]. Opt. Express, 2010, 18(5): 4275~4288
[16] Sun Yiling, Jiang Xiaoqing, Wang Minghua. Analysis of general self-imaging positions in multimode interference couplers[J]. Acta Optica Sinica, 2004, 24(6): 759~762
[18] Sun Yiling, Jiang Xiaoqing, Wang Minghua. Multimode interference couplers and their applications in optical communication system[J]. Study on Optical Communications, 2004, (2): 67~70
[20] H. Hertz. Compact bulk optical 90° hybrid for balanced phase diversity receivers[J]. Electron. Lett., 1989, 25(22): 1518~1519
[21] W. R. Leeb. Realization of 90° and 180° hybrids for optical frequencies[J]. Arch Elek überfragungv, 1983, 37(5/6): 203~206
[22] R. Garreis, Carl Zeiss. 90° optical hybrid for coherent receivers[C]. SPIE, 1991, 1522: 210~219
[23] M. Bopp, G. Hüther, Th. Spatscheck et al.. BPSK homodyne and DPSK heterodyne receivers for free-space communication with NdHost lasers[C]. SPIE, 1991, 1522: 199~209
[24] D. F. Hornbachner, M. A. Schreiblehner, W. R. Leeb et al.. Experimental determination of power penalty contributions in an optical costas-type phase-locked loop receiver[C]. SPIE, 1992, 1635: 10~18
[25] J. Horwath, F. David, M. Knapek et al.. Coherent transmission feasibility analysis[C]. SPIE, 2005, 5712: 13~23
[28] Liu Liren, Yan Aimin, Luan Zhu et al.. Free-space optical hybrid of birefringence[P]. China Patent, CN200610026338.X,2006
[29] Liu Liren, Liu De′an, Yan Aimin et al.. Free-space optical hybrid with controlling phase shift by electric field[P]. China Patent, CN 200610026339.4,2006