Advances in femtosecond single-crystal sum-frequency generating optical parametric oscillators

The effect of compensating the group velocity mismatch between the orthogonal pump components on the conversion efficiency of the optical parametric oscillators (OPOs) was investigated. A femtosecond single-crystal sum-frequency generating optical parametric oscillators (OPO) based on a Ti:sapphire laser pumped KTiOPO4 crystal was used. presented. The crystal was phase matched for a specific signal wavelength corresponding to the operational wavelength of the laser. The crystal was also phase-matched for the sum-frequency generations (SFG) of the pump and the signal beams yielded a blue output beam. The conversion efficiency of the OPOs increased by compensating the group velocity mismatch.