Optical parametric oscillator

An in laser technology of applied optical parametric oscillator ( OPO abbr, English optical parametric oscillator) essentially consists of an optically nonlinear crystal such as beta - barium borate ( BBO ), in an optical resonator. The crystal generated from a pump wave irradiated on the non-linear three- wave interaction in a parametric process signal and idler radiation. Either the generated idler or signal radiation is partially fed back via a mirror. This increases with each pass through the crystal, the energy of the resonant wave. Thus, a parametric amplification with appreciable conversion efficiency take place because the process does not have to start from the parametric noise.

From energy conservation, it follows that the sum of the quantum energy of the generated signal, and idler radiation of the quantum energy of the corresponding pump radiation. However, not only the energy conservation, but also the phase matching condition must be fulfilled for efficient frequency conversion.

With this method one can produce laser radiation with a wavelength outside the wavelengths of available active laser media.

Further can be produced ( corresponding to the sum or difference of the respective quantum of energy) of two light waves irradiated with non-linear optical crystals, the sum or difference frequency.

The first tunable optical parametric oscillators were developed in 1965 at Bell Laboratories by Joseph A. Giordmaine and Robert C. Miller.