Tunable microwave photonics filter with dual pass-band based on PM-FBG and PS-FBG

摘要

In this paper, a dual pass-band microwave photonics filter with simple, commercial structure is proposed and demonstrated. The key devices are the specially designed polarization maintaining fiber Bragg grating and the phase shift fiber Bragg grating. They are employed to extract out two orthogonally polarized sidebands and remove the undesired sideband, respectively. The simulation results show that without any extra operations or electrical processing, the dual pass-band can be achieved with the two central frequencies of 3.5GHz and 8GHz when the frequency spacing between the two orthogonally polarized sidebands is 12GHz, their 3-dB bandwidth are about 500MHz. The central frequencies of the two pass-bands can be simply tuned by adjusting the frequency spacing in a range of 4GHz. In addition, the spurious free dynamic ranges for the two pass-bands are 75.71dBHz(2/3) and 70.17dBHz(2/3) respectively. Finally, a brief experiment is also carried out to demonstrate the feasibility.