Optical parametric oscillators

Abstract
Optical parametric oscillators simultaneously generate two beams of coherent light that are widely tunable in wavelength. This flexibility makes them a popular tool in various areas of scientific research, reports Neil Savage. Optical parametric oscillators (OPOs) are convenient sources of coherent light that suit numerous scientific applications, including various types of spectroscopy, multiphoton excitation, and light detection and ranging.In contrast to a laser, which relies on stimulated emission from a gain medium, OPOs use a nonlinear crystal to convert a pump beam into an idler beam and a signal beam.