Abstract

A quadrature phase-shift keying (QPSK) coherent photodetector chip consisting of a 4×4 multimode interference 90° optical hybrid and a four-channel evanescent photodetector array is designed and fabricated with its photo-response in the L-band characterized. The metal organic chemical vapor deposition regrowth method is adopted to realize active–passive monolithic integration. The chip exhibits a low dark current below 100 nA for each photodetector in the array, a low excess loss of 0.85 dB, a common mode ratio rejection better than 13.6 dB, and a phase deviation within ±10° over the 40 nm wavelength span.

© 2023 Chinese Laser Press

Monolithic InP receiver chip with a 90° hybrid and 56 GHz balanced photodiodes

Patrick Runge, Stefan Schubert, Angela Seeger, Klemens Janiak, Jens Stephan, Dirk Trommer, Patrick Domburg, and Mads Lønstrup Nielsen
Opt. Express 20(26) B250-B255 (2012)

Compact optical 90° hybrid employing a tapered 2×4 MMI coupler serially connected by a 2×2 MMI coupler

Seok-Hwan Jeong and Ken Morito
Opt. Express 18(5) 4275-4288 (2010)

Polarization-insensitive 90° optical hybrid using silica-based PLC

Pan Pan, Liangliang Wang, Qinghai Liu, Shengbao Zhan, Peng Wang, Lingli Li, and Junming An
Appl. Opt. 62(1) 75-82 (2023)

Ultra-compact optical 90° hybrid based on a wedge-shaped 2 × 4 MMI coupler and a 2 × 2 MMI coupler in silicon-on-insulator

Wei Yang, Mei Yin, Yanping Li, Xingjun Wang, and Ziyu Wang
Opt. Express 21(23) 28423-28431 (2013)

A 16 GHz silicon-based monolithic balanced photodetector with on-chip capacitors for 25 Gbaud front-end receivers

Mohammed Shafiqul Hai, Meer Nazmus Sakib, and Odile Liboiron-Ladouceur
Opt. Express 21(26) 32680-32689 (2013)