Study on a quasi-CW Nd:YAG frequency-doubled laser at 660nm
A QCW Nd:YAG intracavity frequency doubled red laser was made. Using a flat—flat laser cavity, 2 Kr-lamps, KTP crystal and an AO Q-switch, 2 W output power at 660 nm was obtained. The relationship between laser cavity length and output power is analyzed.
Nearly-Noncritical Phase Matching in MgO:LiNbO3 Optical Parametric Oscillators
We propose and demonstrate nearly-noncritical phase-matched optical parametric oscillation in MgO:LiNbO3 crystal by temperature tuning. The tuning range of the OPO was 800-1700 nm with temperatures tuning from 83°C to 224.2 °C.
Threshold effect in Mg‐doped lithium niobate
Optical absorption spectra were obtained after reducing (i.e., vacuum annealing) a series of LiNbO3 crystals grown from melts having various Mg concentrations and Li/Nb ratios. A band peaking at 500 nm, and assigned to oxygen vacancies containing two electrons, was the only absorption present in one set of crystals following reduction. In contrast, two overlapping bands peaking near 1200 and 760 nm were present in the other set of crystals immediately after the reduction. The 1200‐nm band is assigned to a previously unreported electron trap and the 760‐nm band to oxygen vacancies containing only one electron. These data are interpreted in terms of a threshold level for Mg doping; however, the threshold Mg doping level is not a constant but depends on the ratio of Mg ions to Li vacancies.