High common mode rejection ratio InP 90 degrees optical hybrid in ultra-broadband at 60 nm with deep-rigded waveguide based on x 4 MMI coupler*
Author(s): Lu, ZQ (Lu, Zi-Qing); Han, Q (Han, Qin); Ye, H (Ye, Han); Wang, S (Wang, Shuai); Xiao, F (Xiao, Feng); Xiao, F (Xiao, Fan)
Source: CHINESE PHYSICS B Volume: 29 Issue: 5 Article Number: 054206 DOI: 10.1088/1674-1056/ab7b52 Published: MAY 2020
Abstract: An InP optical 90 degrees hybrid based on a x 4 MMI coupler with a deep ridged waveguide is designed and fabricated. The working principle of the 90 degrees hybrid is systematically introduced. Three-dimensional beam ropagation method (3D BPM) is used to optimize the structure parameters of the 90 degrees hybrid. The designed compact structure is demonatrated to have a low excess loss less than -0.15 dB, a high common mode rejection ratio better than 40 dB, and a low relative phase deviation less than +/- 2.5 degrees. The designed hybrid is manufactured on a sandwitched structure deposited on an InP substrate. The measured results show that the common mode rejection ratios are larger than 20 dB in a range from 1520 nm to 1580 nm. The phase deviations are less than +/- 5 degrees in a range from 1545 nm to 1560 nm and less than +/- 7 degrees across the C band. The designed 90 degrees optical hybrid is suitable well for realizing miniaturization, high-properties, and high bandwidth of coherent receiver.
Accession Number: WOS:000539985500001
ISSN: 1674-1056
eISSN: 1741-4199
Full Text: https://iopscience.iop.org/article/10.1088/1674-1056/ab7b52