Tunable Microwave Single-Bandpass Photonic Filter Based on Amplified Mems-Based Gires–Tournois Interferometer

We demonstrate a compact microelectromechanical systems based tunable single bandpass microwave photonic filter (MPF). A MEMS gold-platted micro-mirror facing cleaved optical fiber forms a tunable miniature Gires–Tournois interferometer (GTI). The micro-mirror was fabricated by Deep Reactive Ion Etching (DRIE) on silicon on insulator (SOI) wafer. A semiconductor optical amplifier (SOA) is employed simultaneously as a source of a broad optical spectrum and as an optical amplifier. A chirped-fiber Bragg grating is used as a dispersive delay line to provide a time delay to each wavelength slice. The simulation and experimental results are in good agreement showing a linear variation of the MPF center frequency with the separation between the micro-mirror and the fiber facet. The measured tuning range and tuning resolution are 1.3 to 2.5 GHz and 5.85 MHz/µm, respectively. The measured value of the stopband attenuation is more than 20 dB. The maximum value of the 3-dB bandwidth is 258 MHz.