Title :
OSNR Monitoring Technique for DPSK/DQPSK Signals Based on Self-Heterodyne Detection
Author :
Choi, H.Y. ; Takushima, Y. ; Chung, Y.C.
Author_Institution :
Dept. of Electr. Eng., Korea Adv. Inst. of Sci. & Technol., Daejeon
fDate :
7/1/2008 12:00:00 AM
Abstract :
We describe a new method for monitoring the ldquoin-bandrdquo optical signal-to-noise ratio (OSNR) of differential phase-shift-keying (DPSK) and differential quadrature phase-shift-keying (DQPSK) signals. This technique estimates the OSNR by analyzing the radio frequency spectrum obtained by the self-heterodyne detection. The results show that the performance of the proposed technique is not sensitive to the effects of chromatic dispersion and polarization-mode dispersion. In addition, this technique can be used for monitoring the polarization-scrambled signals. For a demonstration, we measure the OSNR of the polarization-scrambled 10-Gb/s DPSK and 20-Gb/s DQPSK signals in a 640-km-long transmission link.
Keywords :
differential phase shift keying; heterodyne detection; optical communication; optical noise; optical variables measurement; quadrature phase shift keying; DPSK; DQPSK; OSNR; bit rate 10 Gbit/s; bit rate 20 Gbit/s; chromatic dispersion; differential phase shift keying; differential quadrature phase shift keying; distance 640 km; optical signal-to-noise ratio; polarization mode dispersion; polarization scrambled signals; radio frequency spectrum; self heterodyne detection; transmission link; Chromatic dispersion; Differential quadrature phase shift keying; Frequency estimation; Monitoring; Optical noise; Optical sensors; Phase shift keying; Polarization; Radio frequency; Signal to noise ratio; Differential phase-shift keying (DPSK); differential quadrature phase-shift keying (DQPSK); optical signal-to-noise ratio (OSNR); self-heterodyne detection;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2008.924649
