Wavelength Tuning of Multimode Interference Fiber Lasers: A Review

Abstract

Herein, the main aspects of fiber lasers are summarized where multimode interference (MMI) is the underlying phenomenon for the wavelength tuning mechanism. Also, 15 years of work in the field are covered, from its first report, in 2005, to the most recent publications, in 2020. In addition to the historical perspective, insights into the different mechanisms are also provided that are exploited to tune the spectral response of the MMI filters used in fiber lasers, among which are free space, optofluidic, stress optic, thermo optic, and nonlinear mechanisms.