title: Tunable microwave filter that uses a high-birefringent fiber and a differential-group-delay element.
abstract: We propose and experimentally demonstrate a novel and simple photonic microwave notch filter that uses a high-birefringent fiber that gives a fixed differential group delay (DGD), together with a DGD element that gives a tunable DGD. This configuration overcomes the problems of optical coherence interference and chromatic dispersion, which may occur in schemes that use fiber delay lines or fiber gratings. Also presented is a theoretical analysis for the performance of the microwave filter that uses the present configuration. The present scheme provides a continuous tuning capability for changing the notch frequency. Measured notch rejection is greater than 40 dB. This scheme can operate over a wide wavelength range of the optical carrier. There is good agreement between experiment results and theoretical analysis.
authors.affiliation: Network Technology Research Centre, Research Techno Plaza, Nanyang Technological University, Singapore 637553. ngxstone@pmail.ntu.edu.sg
authors.forename: G X
authors.initials: GX
authors.lastname: Ning
authors.forename: S
authors.initials: S
authors.lastname: Aditya
authors.forename: P
authors.initials: P
authors.lastname: Shum
authors.forename: N
authors.initials: N
authors.lastname: Liu
authors.forename: Y D
authors.initials: YD
authors.lastname: Gong
authors.forename: Chao
authors.initials: C
authors.lastname: Lu