[1] Fandino J S, Munoz P. Manufacturing tolerance analysis of an MMI-based 90° optical hybrid for InP integrated coherent receivers[J]. IEEE Photonics J., 2013, 5(2): 7900512.
[2] Fandino J S, Munoz P, Capmany J, et al. Tolerance analysis of a 4×4 MMI-based 90° optical hybrid for 100 G coherent receivers[C]// European Conf. on Integrated Optics.
[3] Pan P, An J M, Wang H J, et al. The design and error analysis of 90° hybrid based on InP 4×4 MMI[J]. Optics Communications, 2015, 351: 63-69.
[4] Pennings E C M, Deri R J, Bhat R, et al. Ultracompact, all-passive optical 90°-hybrid on InP using self-imaging[J]. IEEE Photon. Technol. Lett., 1993, 5(6): 701-703.
[5] Halir R, Roelkens G, Ortega-Monux A, et al. High-performance 90° hybrid based on a silicon-on-insulator multimode interference coupler[J]. Opt. Lett., 2011, 36(2): 178-180.
[6] Liang X R, Ma W P, Jiang X, et al. Optical 90° hybrid based on silicon-on-insulator 4×4 multimode interference coupler for integrated coherent receiver application[C]// Optical Communications and Networks, 2013: 1-3.
[7] Lu Z Q, Han Q, Ye H, et al. High common mode rejection ratio InP 90° optical hybrid in ultra-broadband at 60 nm with deep-ridged waveguide based on 4×4 MMI coupler[J]. Chin. Phys. B, 2020, 29(5): 054206.