Broadly, independent-tunable, dual-wavelength mid-infrared ultrafast optical parametric oscillator

TL;DR

This paper presents a dual-wavelength mid-infrared optical parametric oscillator with independent tunability over 30 THz, enabling ultrafast pulse generation and potential broadband phase locking for THz applications.

Contribution

It introduces a novel two-crystal, singly-resonant ring cavity design with independent tunability of two idler wavelengths in the mid-infrared range.

Findings

Achieved independent tunability over 30 THz in 2.9-4.2 μm range

Demonstrated synchronized dual-wavelength generation with cascaded quadratic nonlinear effect

Indicated potential for broadband optical self-phase locking

Abstract

We demonstrate a two-crystal mid-infrared dual-wavelength optical parametric oscillator, synchronously pumped by a high power femtosecond Yb:fiber laser. The singly-resonant ring cavity, containing two periodically poled lithium niobate crystals, is capable of generating two synchronized idler wavelengths, independently tunable over 30 THz in the 2.9 - 4.2 {\mu}m wavelength region, due to the cascaded quadratic nonlinear effect. The independent tunability of the two idlers makes the optical parametric oscillator a promising source for ultrafast pulse generation towards the THz wavelength region, based on different frequency generation. In addition, the observed frequency doubled idler within the crystal indicates the possibility to realize a broadband optical self-phase locking between pump, signal, idler and higher order generated parametric lights.