All-fiber CW optical parametric oscillator tuned from 1642.5 to 1655.4 nm by a low-loss SMS filter

Abstract

A continuous-wave tunable all-fiber optical parametric oscillator (FOPO) was demonstrated with a single-mode–multimode–single-mode (SMS) device used as wavelength selection filter. A highly nonlinear fiber (HNLF) was used to provide nonlinear gain, and two cascaded SMS fiber structures, having low insertion losses and containing multimode fibers of different lengths and core diameters, were used for effective wavelength selection. The maximum FOPO signal power was 0.5 W at 1642.5 nm, with 2 W of pump light incident on the HNLF end face. The power stability of the FOPO signal output was better than 0.2 dB over 30 min. A wavelength tuning range from 1642.5 to 1655.4 nm was realized by stretching a multimode fiber in the SMS device.