Octave-spanning supercontinuum generation from off-axis Raman oscillation in a monolithic KTP crystal

We report generation of a visible and near-infrared super-continuum from a high-gain, ultra-broadband, and mirrorless Raman oscillator in a monolithic KTP crystal. The plane transverse to the pump axis resonates and traps off-axis Stokes waves and their frequency-upconverted components bouncing between two crystal surfaces via total internal reflection. The Raman gain is maximized with the Stokes polarization perpendicular to the plane of reflections. When pumped by a Q-switched Nd:YAG laser, the monolithic oscillator generates quasi-mode-locked Stokes pulses with octave-spanning spectral groups across the visible and near-infrared spectra between 540 and 1800 nm. (C) 2021 Optical Society of America

Automated summary

The researchers successfully generated a visible and near-infrared super-continuum in a monolithic KTP crystal using a high-gain, ultra-broadband Raman oscillator. By maximizing Raman gain and aligning Stokes polarization perpendicular to the plane of reflections, the oscillator produced quasi-mode-locked Stokes pulses across the visible and near-infrared spectra.