A novel integrable optical analog-to-digital converter (OADC) scheme based on phase-shifted optical quantization has been proposed for years, the quantization module of which is mainly composed of a 1×2 multi-mode interference (MMI) coupler, a phase modulator and a 4×4MMI. Although the manufacture technology of 1×2 MMI and phase modulator has been very mature, the 4×4MMI on a silicon-on-insulator (SOI) substrate with superior performance has not been realized. Since the 4×4MMI is crucial for the realization of the OADC, we designed and fabricated a 4×4 MMI coupler on SOI substrate. The width and length of the multi-mode section are 10.2 um and 182.6 um respectively. Measurement results show that the imbalance of the four output ports at 1550-nm is around 1.9 dB, while the insertion losses are 5.6 dB.

Date Published: 5 August 2015
PDF: 6 pages
Proc. SPIE 9619, 2015 International Conference on Optical Instruments and Technology: Optoelectronic Devices and Optical Signal Processing, 961906 (5 August 2015); doi: 10.1117/12.2193491

Published in SPIE Proceedings Vol. 9619:
2015 International Conference on Optical Instruments and Technology: Optoelectronic Devices and Optical Signal Processing
Yi Dong; Chao Lu; Jian Wu; Zhaohui Li, Editor(s)