[1] Xu Z Y, Lyu T, Sun X H. Interleaved subwavelength gratings strip waveguide based TM pass polarizer on SOI platform[J]. IEEE Photonics Journal, 2020, 12(2): 1-10.

[2] Tao S H, Fang Q, Song J F, et al. Cascade wide-angle Y-junction 1×16 optical power splitter based on silicon wire waveguides on silicon-on-insulator[J]. Optics Express, 2008, 16(26): 21456-21461.

[3] YamadaH, ChuT, IshidaS, et al.Optical directional coupler based on Si-wire waveguides[C]∥ First IEEE International Conference on Group IV Photonics, September 29-October 1, 2004, Hong Kong, China.New York: IEEE Press, 2004: 145- 147.

[4] Soldano L B. Pennings E C M. Optical multi-mode interference devices based on self-imaging: principles and applications[J]. Journal of Lightwave Technology, 1995, 13(4): 615-627.

[5] Sheng Z, Wang Z Q, Qiu C, et al. A compact and low-loss MMI coupler fabricated with CMOS technology[J]. IEEE Photonics Journal, 2012, 4(6): 2272-2277.

[6] Roth JP, KühlerT, GrieseE. A comparison of higher-order graded-index MMI-based splitters in thin glass sheets for PCB integration[C]∥2018 IEEE 22nd Workshop on Signal and Power Integrity (SPI), May 22-25, 2018, Brest, France.New York: IEEE Press, 2018: 1- 4.

[7] Ren F, Chen W, Zhangsun T W, et al. Variable-ratio mode-insensitive 1×2 power splitter based on MMI couplers and phase shifters[J]. IEEE Photonics Journal, 2018, 10(5): 1-12.

[8] Xu Y, Xiao J B. An ultracompact polarization-insensitive silicon-based strip-to-slot power splitter[J]. IEEE Photonics Technology Letters, 2016, 28(4): 536-539.

[9] MengC, Qiu JF, TianY, et al.A broadband compact 1×3 power splitter designed with inverse design method[C]∥2016 15th International Conference on Optical Communications and Networks (ICOCN), September 24-27, 2016, Hangzhou, China.New York: IEEE Press, 2016: 1- 3.

[10] Maese-Novo A, Halir R, Romero-García S, et al. Wavelength independent multimode interference coupler[J]. Optics Express, 2013, 21(6): 7033-7040.

[11] Pan C. Rahman B M A. Compact polarization-independent MMI-based 1×2 power splitter using metal-cap silicon-on-insulator waveguide[J]. IEEE Photonics Journal, 2016, 8(3): 1-14.

[12] Dai D, He S. Optimization of ultracompact polarization-insensitive multimode interference couplers based on Si nanowire waveguides[J]. IEEE Photonics Technology Letters, 2006, 18(19): 2017-2019.

[13] Dai D X, He S L. Proposal for diminishment of the polarization-dependency in a Si-nanowire multimode interference (MMI) coupler by tapering the MMI section[J]. IEEE Photonics Technology Letters, 2008, 20(8): 599-601.

[14] 周桐宇, 李丽娟, 任姣姣, 等. 基于FDTD的玻璃纤维增强复合材料脉冲太赫兹无损检测[J]. 光学学报, 2020, 40(12): 1226002.

    Zhou T Y, Li L J, Ren J J, et al. Pulsed terahertz nondestructive testing of glass fiber reinforced plastics based on FDTD[J]. Acta Optica Sinica, 2020, 40(12): 1226002.

[15] Shi Y C, Anand S, He S L. A polarization-insensitive 1310/1550-nm demultiplexer based on sandwiched multimode interference waveguides[J]. IEEE Photonics Technology Letters, 2007, 19(22): 1789-1791.

[16] Wang Z C, Dai D X, He S L. Polarization-insensitive ultrasmall microring resonator design based on optimized Si sandwich nanowires[J]. IEEE Photonics Technology Letters, 2007, 19(20): 1580-1582.

[17] Lee C C, Chen H L, Hsu J C, et al. Interference coatings based on synthesized silicon nitride[J]. Applied Optics, 1999, 38(10): 2078-2082.

[18] Guler I. Optical and structural characterization of silicon nitride thin films deposited by PECVD[J]. Materials Science and Engineering: B, 2019, 246: 21-26.

[19] Wang QF, LiuS, Tang HH, et al.Study on a-Si: H and SiNx films for tunable filter[C]∥2016 25th Wireless and Optical Communication Conference (WOCC), May 21-23, 2016, Chengdu, China. New York: IEEE Press, 2016: 1- 4.

[20] Fu Y F, Ye T, Tang W J, et al. Efficient adiabatic silicon-on-insulator waveguide taper[J]. Photonics Research, 2014, 2(3): A41-A44.

[21] 汪静丽, 陈子玉, 陈鹤鸣. 基于Si3N4/SiNx/Si3N4三明治结构的偏振无关1×2多模干涉型解复用器的设计[J]. 物理学报, 2020, 69(5): 054206.

    Wang J L, Chen Z Y, Chen H M. Design of polarization-insensitive 1×2 multimode interference demultiplexer based on Si3N4/SiNx/Si3N4 sandwiched structure[J]. Acta Physica Sinica, 2020, 69(5): 054206.

[22] W Li P L, Chen Y, Zhang Y F, et al. Polarization independent 1×3 equal optical power splitter based on self-collimation effect in two-dimensional photonic crystal[J]. Optical Engineering, 2019, 58(9): 097103.

[23] Han X M, Yu Y L. Optimization of a thermally tuned silicon-based reconfigurable optical power splitter with thermal isolations[J]. Optical Engineering, 2017, 56(1): 017106.

[24] Liu J, Zhang W J, Liu S Z. H2-Ar dilution for improved c-Si quantum dots in P-doped SiNx: H thin film matrix[J]. Applied Surface Science, 2017, 396: 235-242.