Tunable β-barium borate optical parametric oscillator: operating characteristics with and without injection seeding

Bandwidth studies of an injection-seeded β-barium borate optical parametric oscillator

“…We also measured the pulse duration of the OPO signal and observed it to increase with increasing pump power, in agreement with the measurements of Fix et al 4 In these measurements we removed the telescope in the pump beam, and to reduce the size of the pump beam to 5.5 mm we used a pinhole. In this case the threshold increased to 50 mJ.…”

“…A free-running OPO does not provide the required narrow-band radiation; however, the bandwidth can be reduced considerably by use of intracavity elements such as gratings 2 andétalons 3 or by injection seeding with a narrow-band laser on either the signal or the idler wavelength. 4 When the bandwidth of the pump laser is sufficiently small, the energy conservation condition for the OPO ensures that the signal and the idler have comparable bandwidths. Hence, if one of these waves is constrained to be narrow band, then the other will be likewise constrained.…”

Nanosecond sum-frequency generating optical parametric oscillator using simultaneous phase matching

“…However, conversion to red wavelengths usually requires cascading harmonic generation with optical parametric generation. Generation of red laser beams using optical parametric oscillators (OPOs) that are pumped by various harmonics of the Nd:YAG laser were previously reported in the nanosecond pulsed regime [1][2][3][4]; however, the overall 1064-nm-to-visible energy conversion efficiencies of these systems are typically below 10%. A nanosecond periodically poled lithium niobate (PPLN) OPO pumped by the second-harmonic of a Q-switched Nd:YAG laser was reported to achieve a maximum of 12% conversion efficiency [5]; however, the output energy was limited due to the damage threshold of the lithium niobate crystal that is imposed by aperture limitations.…”

Control of frequency chirp in nanosecond-pulsed laser spectroscopy 2 A long-pulse optical parametric oscillator for narrow optical bandwidth

“…Other observations of the onset of broadband unseeded operation in dispersed ␤-barium borate OPO output radiation, as the phasematching angle is varied stepwise to shift free away from the (seeded) signal wavelength, s , have also been reported [34][35][36] and modeled. 34,36 We emphasize that these earlier studies were averaged over the time-profile of the OPO output pulse, whereas we show OPO pulse dynamics in Fig.…”