Figen, Ziya Gürkan2016-01-082016-01-082005http://hdl.handle.net/11693/18483Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Science of Bilkent University, 2005.Thesis (Ph. D.) -- Bilkent University, 2005.Includes bibliographical references leaves 122-143.In this thesis, we demonstrate a technique for highly efficient red beam generation using nanosecond upconversion optical parametric oscillators based on KTiOAsO4 crystals that are simultaneously phase matched for optical parametric generation and sum-frequency generation. Pumped at a wavelength of 1064 nm by a Qswitched Nd:YAG laser, these devices produce red output beams at 627 nm with 1064-nm-to-627-nm energy conversion efficiencies reaching 20% for the singlepass pumping and 30% for the double-pass pumping. Our devices are simpler in architecture compared to other devices converting nanosecond Nd:YAG laser radiation into red wavelengths. A typical nanosecond upconversion optical parametric oscillator is comprised of three cavity mirrors which are all high reflectors at the signal wavelength (1525 nm), a 2-cm-long KTiOAsO4 crystal, and an intracavity retarder plate for rotating the polarization of the signal beam. The total cavity length is under 5 cm. With its small size, the device can be shaped into a module to be placed in front of Nd:YAG lasers for highly efficient red beam generation. The single-pass sum-frequency generating optical parametric oscillator is the first demonstration of a nanosecond optical parametric oscillator using simultaneous phase matching. We have fully characterized these devices in terms of their energy output as functions of polarization rotation angle and input pump energy, time profiles, spatial beam profiles, and spectra of the output. In this thesis, we also present our work on modelling continuous-wave intracavity optical parametric oscillators.xvi, 143 leavesEnglishinfo:eu-repo/semantics/openAccessNonlinear frequency conversionOptical parametric oscillatorsSumfrequency generationSimultaneous phase matchingQ-switched Nd:YAG laserRed beam generationModelling continuous-wave intracavity optical parametric oscillatorsTK7872.O7 F54 2005Oscillators, Electric.Parametric devices.Thesis