Multi-structured-beam optical parametric oscillator.

Abstract

Structured beams, conventionally generated through the spatial mode conversion of the Gaussian laser beams, have attracted great interest in recent years. Optical parametric oscillators (OPOs) have demonstrated the potential for the generation of tunable structured beams directly from an input pump source. However, to date, a particular OPO design has been shown to produce such beams only in a specific configuration and different spatial structured beams require different system architectures. Here, we report the generation of multiple-structured beams from a single OPO device. Using a vortex-beam-pumped ultrafast OPO in singly-resonant oscillator design and through the control of the mode structure of the resonant beam using a simple intracavity aperture, we generate vortex, Airy, vortex Airy, and Gaussian signal beams over a tunable wavelength range across 1457-1680 nm, simultaneous with vortex beam in the non-resonant idler across 2902-3945 nm, from different ports of the device. The signal and idler vortices have output power in excess of 1 W and maximum vortex order of li=2, while the Airy beam and vortex Airy beam have output power of more than 200 mW. The generic experimental design can be used to provide multi-structured spatial beams with broad tunability across different spectral regions by proper selection of pump laser and nonlinear material and in all times-scales from continuous-wave to ultrafast femtosecond domain.