Abstract

We propose and demonstrate an optical $60°$ hybrid for demodulating optical signals with six-level DPSK modulation format. The proposed device consisting of a paired-interference $2:6\mathrm{MMI}$ coupler, phase shifters, and $2:2\mathrm{MMI}$ couplers with an asymmetric splitting ratio of $72:28$ exhibited hexagonal phase response over a C-band range.

© 2011 Optical Society of America

Optical 45° hybrid for demodulating 8-ary DPSK signal

Seok-Hwan Jeong and Ken Morito
Opt. Express 18(8) 8482-8490 (2010)

Optical 90° hybrid with broad operating bandwidth of 94 nm

Seok-Hwan Jeong and Ken Morito
Opt. Lett. 34(22) 3505-3507 (2009)

Simultaneous all-optical demodulation and format conversion for multi-channel (CS)RZ-DPSK signals

Zheng Zhang, Yu Yu, and Xinliang Zhang
Opt. Express 19(13) 12427-12433 (2011)

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)

Simple analytical calculation and experimental demonstration of optical 90° hybrids based on tapered 2×4 and 2×2 multimode interference couplers

Seok-Hwan Jeong and Ken Morito
J. Opt. Soc. Am. B 28(1) 159-164 (2011)