Fiber loop mirror based single-platform multifunctional Michelson-Gires-Tournois filter

摘要

A single platform multifunctional fiber optic filter is presented. The filter is based on a Michelson-Gires-Tournois Interferometric (MGTI) structure, which makes use of high dynamic range fiber loop mirrors (FLM) for the tunability of the required reflectance. Path length control is another degree of freedom which provide the multifunctionality in the optical transfer function of the filter. The optical filter can be configured to suppress optical side bands, shape the amplitude of optical combs, or perform spectral slicing for signal processing. Rectangular pass-band transfer functions (TF) with tunable center frequency (tens of GHz) and tunable frequency bandwidth (BW) with side lobe suppression of more than 20 dB and ripple of 0.2 dB is obtained. Modifications in the resonator reflectance (99%) and optical paths can change the TF to notch type with 250 MHz bandwidth. Further reflectance modification (99%) leads to TF with linear portions, where the slope can be adjusted by adjusting the resonator reflectance. Finally, sinusoidal transfer function of varying period completes the set of obtainable TF using a dual Gires-Tournois cavity MGTI configuration in a single photonic platform.