title: Robust optical signal-to-noise ratio monitoring scheme using a phase-modulator-embedded fiber loop mirror.
abstract: We propose and experimentally demonstrate a novel in-band optical signal-to-noise ratio (OSNR) monitoring technique using a phase-modulator-embedded fiber loop mirror. This technique measures the in-band OSNR accurately by observing the output power of a fiber loop mirror filter, where the transmittance is adjusted by an embedded phase modulator driven by a low-frequency periodic signal. The measurement errors are less than 0.5 dB for an OSNR between 0 and 40 dB in a 10 Gbit/s non-return-to-zero system. This technique was also shown experimentally to have high robustness against various system impairments and high feasibility to be deployed in practical implementation.
authors.affiliation: Department of Information Engineering, The Chinese University of Hong Kong, China. ycku2@ie.cuhk.edu.hk
authors.forename: Yuen-Ching
authors.initials: YC
authors.lastname: Ku
authors.forename: Chun-Kit
authors.initials: CK
authors.lastname: Chan
authors.forename: Lian-Kuan
authors.initials: LK
authors.lastname: Chen