title: Photonic crystal fiber based Mach-Zehnder interferometer for DPSK signal demodulation.
abstract: We demonstrate a novel fiber-based in-line DPSK demodulator using an in-fiber Mach-Zehnder interferometer (MZI). The device is fabricated by mismatch splicing of a photonic crystal fiber (PCF) with standard single mode fibers. The spectral characteristics at different PCF lengths are analyzed. The envelope of the interference fringes show a period that is inversely proportional to the PCF length, and is attributed to the periodic coupling between the core mode and the cladding mode. Error free demodulations of 10-Gb/s RZ- and NRZ-DPSK signals have been demonstrated using the in-fiber PCF-MZI demodulator with only 3-m PCF to introduce 91-ps delay. Wideband DPSK demodulation has also been achieved.
authors.affiliation: Department of Electronic Engineering and Center for Advanced Research in Photonics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: Jiangbing
authors.initials: J
authors.lastname: Du
authors.forename: Yongheng
authors.initials: Y
authors.lastname: Dai
authors.forename: Gordon K P
authors.initials: GK
authors.lastname: Lei
authors.forename: Weijun
authors.initials: W
authors.lastname: Tong
authors.forename: Chester
authors.initials: C
authors.lastname: Shu