Tunable microwave filter that uses a high-birefringent fiber and a differential-group-delay element.
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.
Ning
G X
GX
Network Technology Research Centre, Research Techno Plaza, Nanyang Technological University, Singapore 637553. ngxstone@pmail.ntu.edu.sg
Aditya
S
S
Shum
P
P
Liu
N
N
Gong
Y D
YD
Lu
Chao
C