Optical minimum-shift-keying transmitter based on a monolithically integrated quad Mach-Zehnder in-phase and quadrature modulator.
We propose and demonstrate an optical minimum-shift-keying (MSK) transmitter using a single-quad Mach-Zehnder (MZ) in-phase and quadrature modulator, where four sub-Mach-Zehnder modulators are monolithically integrated on a main MZ superstructure. Using the proposed transmitter, a MSK signal at bit rate of B could be successfully generated by orthogonally superposing two low-speed (B/2) carrier-suppressed return-to-zero differential phase-shift-keying streams with a relative time offset, 1/B. MSK signals at bit rate of 20 and 80 Gbits/s were successfully generated using the proposed MSK transmitter. A continuous changed phase trajectory of the obtained MSK was confirmed using a complex spectrum analyzer. The filtering tolerance of the MSK was also characterized using a bandwidth-variable tunable filter.
Lu
Guo-Wei
GW
National Institute of Information and Communications Technology, Tokyo, Japan. gwlu@nict.go.jp
Sakamoto
Takahide
T
Chiba
Akito
A
Kawanishi
Tetsuya
T
Miyazaki
Tetsuya
T
Higuma
Kaoru
K
Ichikawa
Junichiro
J