Ding Xin

Nearly-noncritical phase matching in MgO : LiNbO3 optical parametric oscillators

We have proposed and demonstrated a nearly-noncritical phase-matched (NCPM) optical parametric oscillation (OPO) in an MgO:LiNbO3 crystal with 5 mol% MgO by temperature tuning. By giving up perfect NCPM, the practical tuning range for the OPO is increased by two times. For the crystal, the operated temperature decreases with the phase-matching angle at degeneracy. With a cutting angle of 82° instead of the noncritical case of 90°, the tuning range was increased. In order to obtain a sufficiently high output pulse energy for both signal and idler throughout the entire tuning range, five sets of mirrors were used for the resonator. The tuning range of the OPO was 800-1700 nm with temperatures tuning from 83°C to 224.2°C. The output energy was about 6.45 mJ with a conversion efficiency of nearly 13%. The bandwidth of the output was 1.0-1.1 nm.

High Power Diode-End-Pumped Nd:YAG 946-nm Laser and Its Efficient Frequency Doubling

We report a high power operation of the 4F3/2→4I9/2 transition in diode-end-pumped laser at 946 nm. The maximum output of 5.1 W is obtained with a short linear plano-concave cavity, and the slope efficiency is 24.5% at incident pump power of 23.3 W. To our knowledge, this is the highest value of the LD-pumped Nd:YAG 946 nm lasers that employ the conversional Nd:YAG rod as the gain medium. By intracavity frequency doubling with an LBO crystal, up to 982 mW cw output power in the blue spectral range at 473 nm is achieved at an incident pump power of 10.9 W with a compact three-element cavity, leading to optical-to-optical conversion efficiency of 9%. The conversion efficiency should be increased to 15.1%, if the rather low absorption coefficient of this Nd:YAG is considered.

Laser Diode Pumped 1.54 µm Er:Yb:Phosphate Glass Continuous Wave Compact Laser

We report a cw Er3+:Yb3+ co-doped phosphate glass laser pumped by a laser diode. The maximum output power of 78.3 mW and a slope efficiency of 15.25% were achieved. The laser spectral region was from 1532 nm to 1535 nm, with the peak laser wavelength at 1534 nm. The laser modes and time stability were also measured. The thermal effect had little influence on the output in our experiment.

Pump-tuning KTP optical parametric oscillator with continuous output wavelength pumped by a pulsed tunable Ti:sapphire laser

We report on the implementation of a KTP optical parametric oscillator pumped by a pulsed tunable Ti:sapphire laser. Two major improvements were achieved, including the connection of the signal and idler tuning ranges and the high-output conversion efficiency through the signal and idler tuning ranges. Both in the signal and idler, the continuous output wavelength from 1.261 to 2.532µm was obtained by varying the pump wavelength from 0.7 to 0.98µm. The maximum output pulse energy was 27.2mJ and the maximum conversion efficiency was 35.7% at 1.311µm (signal).