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

Spectral and temporal properties of a scanning injection-seeded β-barium borate optical parametric oscillator pumped by the third harmonic of a 10-Hz Nd:YAG laser have been studied. The seed source was a cw diode laser with a wavelength of 830 nm tunable over a range of 50 GHz. We measured the bandwidth of the seeded optical parameter oscillator, using a two-photon resonance in barium and a Fabry–Perot étalon, to be approximately 400 MHz for pump power levels more than two times above threshold. This is ~2 times the Fourier-transform-limited bandwidth. At lower pump powers the bandwidth was smaller.