High-power continuous-wave operation of a fiber optical parametric oscillator in L and U bands

Abstract

Fiber optical parametric oscillators (OPOs), based on a highly-efficient four-wave mixing process in a χ(3) medium, are reviewed. Their capability to provide very large tuning ranges with high output power is discussed. A novel architecture for CW fiber OPOs is presented, which has allowed us to significantly extend the performance of these devices. To do so we used: (i) a highly-nonlinear fiber (HNLF) as the parametric gain medium; (ii) a narrowband tunable intracavity filter; (iii) a high output coupling fraction from the feedback loop (up to 3dB). With these features, we have been able to obtain excellent performance in terms of output power and tuning range, even with a reduced pump power. With only about 2W of pump power, we have obtained the following performances: (i) tuning range of 254nm; (ii) output power in excess of 1W at some wavelengths; (iii) external conversion efficiency in excess of 60% at some wavelengths; (iv) linewidth as low as 8GHz.This architecture of fiber OPO can be used for providing narrow linewidth tunable high-power CW radiation over hundreds of nanometers. Such sources could find applications in remote sensing, optical communication, nonlinear optics, etc.