Nanosaniye yukarı-çevirim optik parametrik osilatörleri

In this thesis, we demonstrate a technique for highly efficient red beam generationusing nanosecond upconversion optical parametric oscillators based on KTiOAsO4crystals that are simultaneously phase matched for optical parametric generationand sum-frequency generation. Pumped at a wavelength of 1064 nm by a Q-switched Nd:YAG laser, these devices produce red output beams at 627 nm with1064-nm-to-627-nm energy conversion efficiencies reaching 20% for the single-pass pumping and 30% for the double-pass pumping. Our devices are simplerin architecture compared to other devices converting nanosecond Nd:YAG laserradiation into red wavelengths. A typical nanosecond upconversion optical para-metric oscillator is comprised of three cavity mirrors which are all high reflectorsat the signal wavelength (1525 nm), a 2-cm-long KTiOAsO4 crystal, and an in-tracavity retarder plate for rotating the polarization of the signal beam. Thetotal cavity length is under 5 cm. With its small size, the device can be shapedinto a module to be placed in front of Nd:YAG lasers for highly efficient redbeam generation. The single-pass sum-frequency generating optical parametricoscillator is the first demonstration of a nanosecond optical parametric oscillatorusing simultaneous phase matching. We have fully characterized these devices interms of their energy output as functions of polarization rotation angle and inputpump energy, time profiles, spatial beam profiles, and spectra of the output. Inthis thesis, we also present our work on modelling continuous-wave intracavityoptical parametric oscillators.Keywords: nonlinear frequency conversion, optical parametric oscillators, sum-frequency generation, simultaneous phase matching, Q-switched Nd:YAG laser,red beam generation, modelling continuous-wave intracavity optical parametricoscillators.