Tunable continuous-wave doubly resonant optical parametric oscillator by use of a semimonolithic KTP crystal

Dual-loss-modulated Q-switched mode-locked laser intracavity pumped temperature-tuned subnanosecond KTiOPO4 optical parametric oscillator

Using an acousto-optic modulator (AOM) and Cr4+:YAG as the dual-loss modulation, an intracavity KTiOPO4 optical parametric oscillator (OPO) pumped by a simultaneously Q-switched and mode-locked (QML) YVO4/Nd:YVO4 laser was realized. The shortest mode-locking pulse duration of the signal wave at 1573 nm was directly measured as 450 ps at an AOM frequency of 2 kHz and a diode pump power of 10.5 W, corresponding to a peak power of 35.5 kW. The temperature tuning of the output signal wavelength was realized in the range from 1571.99 to 1572.61 nm with a blueshift ratio of 0.027  nm/°C. A set of coupled rate equations for the dual-loss-modulated QML laser pumping intracavity OPO was built for the first time to our knowledge. The numerical solutions were fitted with the experimental results.

Preparation and measurement of tunable high-power sub-Poissonian light using twin beams

Widely frequency tunable bright sub-Poissonian field preparation has been experimentally achieved with quantum-correlated twin beams in the continuously variable regime. The noise of the sub-Poissonian field is reduced to more than 2 dB below the shot-noise level throughout the entire wavelength-tunable range of 7.4 nm. A maximum noise reduction of 45% (2.6 dB) is observed. The statistical distribution of a sub-Poissonian field is also obtained.

Efficient generation of coherent blue light at 440 nm by intracavity-frequency-tripling 1319-nm emission from a Nd:YAG laser

A new route for efficiently generating coherent blue light has been explored based on intracavity effective third-harmonic generation in one partly periodically poled KTiOPO4 crystal placed inside the cavity of a diode-pumped Nd:YAG laser. To achieve efficient conversion, we use a dual-temperature oven to separately control the phase-matching conditions for the two second-order nonlinear processes. In addition, a Fabry-Perot cavity at 660 nm is incorporated into the crystal to increase the blue power significantly. When the laser is Q switched to produce long pulses, an average power of 118 mW is generated at 440 nm at a pump power of 10 W.