Arbitrary spectrum shape optical filter using dynamic gratings in Er doped fiber controlled by synthesis of optical coherence function: simulation and experiments

摘要

Two laser beams traveling in a pumped or un-pumped EDF in opposite directions produce a standing wave. Due to the saturable nature of the gain or absorption of EDF, the dynamic grating is formed. The transmission and reflection characteristics of the grating are determined by the interference of the writing beams, the saturation intensity, and the gain or absorption of the EDF. By modulating the frequency of the writing waves with an appropriate waveform and additionally modulating the phase in one wave, optical coherence function can be synthesized to have an arbitrary shape. It means that we can control the shape and the position of the dynamic grating. In this presentation we confirm, in simulations and experiments, the control of dynamic grating based on the above-mentioned principle.