Yao Ai-Yun

Reducing Thermal Effect in End-Diode-Pumped Laser Crystal by Using a Novel Resonator

We report a new way, i.e. double-end-pumping, to extend the stability range of a laser resonator, in advantage of making the thermal loading be effectively divided between the ends of the laser crystal to reduce the thermal effect, thus to extend the stability range. Using this new way, we experimentally obtained a 2.7-W cw laser source at 671 nm by intracavity frequency doubling of 1342 nm of a Nd:YVO4 laser based on the nonlinear crystal LiB3O5. The maximum pump power is 28 W, which is higher than 13 W of the single-end-pumping.

Mid-infrared generation based on a periodically poled LiNbO3 optical parametric oscillator

We report a nanosecond Nd:YVO4-pumped optical parametric oscillator (OPO) based on periodically poled LiNbO3 (PPLN). Tuning is achieved in this experiment by varying the temperature and period of the PPLN. The design of double-pass singly resonant oscillator (DSRO) and confocal cavity enables the OPO threshold to be lowered considerably, resulting in a simple, compact, all-solid-state configuration with the mid-infrared idler powers of up to 466mW at 3.41μm.

Low-threshold mid-infrared optical parametric oscillator using periodically poled LiNbO3

We report the generation of tunable mid-infrared optical pulses using all-solid-state pumped optical parametric oscillator in a periodically poled lithium niobate. Several ways were used to lower the threshold, resulting in a mean threshold as low as 6.5 mW and an achievement of wavelength conversion in the 2.77-4.04 mum spectral range. Continuous tuning range from 2.97 to 3.25 mum was achieved. The maximum idler output power of 466 mW at the wavelength of 3.41 mum was obtained, which represents an optical-to-optical conversion efficiency of 19% from incident pump power to the idler output.

Efficient Dual-LBO Second-Harmonic Generation by Using a Polarization Modulation Configuration

We analyse the relationship of conversion efficiency with the inter-crystal phase shift by the heuristic theory and propose a novel configuration of two cascaded nonlinear crystals for the second-harmonic generation with the polarization modulation. With this configuration, 70% external doubling efficiency is obtained, which is, to the best of our knowledge, the highest conversion efficiency with LBO crystal external frequency doubling. This configuration provides a simple and effective method to improve the second harmonic conversion efficiency.

Period and temperature tuning of cascaded optical parametric oscillator based on periodically poled LiNbO3

We report the broadly tunable source by a cascaded optical parametric oscillator in the periodically poled LiNbO3 (PPLN) with domain grating period and temperature tuning. The optical parametric oscillator was pumped by a passive Q-switched Nd:YVO4 laser. Multi-wavelength outputs from visible to infrared were obtained. The temperature of the PPLN crystal changed within the range of 70-150°C with different periods of PPLN. The tunable range covered from 433 to 1657nm.

Violet to Infrared Multiwavelength Generation in Periodically Poled Lithium Niobate Pumped by a Q-Switched Nd:YVO4 Laser

Six output wavelengths from violet to infrared have been observed simultaneously from an all-solid-state laser pumped optical parametric oscillator in a periodically poled lithium niobate crystal. The output wavelengths can be tuned by varying the quasi-phase matched period and/or temperature. The pump laser is a diode-pumped passive Q-switched Nd:YVO4 laser operated at 1064 nm. Using a crystal with a 29.9 µm grating period, we measured six wavelengths at 448, 515, 532, 630, 773 and 1546 nm and obtained efficient output. We explain the multiwavelength generation by multiwave coupling theory. This phenomenon may have novel applications in photonic devices.

26W near diffraction limited Q-switched green laser based on a diode-end-pumped master oscillator power amplifier

An efficient acousto-optically Q-switched extracavity frequency-doubled 532nm laser based on a diode-end-pumped master oscillator power amplifier (MOPA) is demonstrated. With a type I non-critically phase-matched LBO, 26W of average power at 532nm in a near diffraction limited mode at a repetition rate of 30kHz was generated under 43W pump power of 1064nm Nd:YVO4 laser, which correspond to a frequency-doubling conversion efficiency of 60%.

Mid-Infrared Optical Parametric Oscillator Based on All-Solid-State-Pumped Periodically Poled LiNbO

We report the tunable mid-infrared generation with a periodically poled LiNbO3 (PPLN). Using an all-solid-state-pumped Nd:YVO4 laser as the pump source and a PPLN nonlinear crystal with grating periods of 28.2-30.8 mum, we have achieved wavelength conversion in the 2.90-4.05 mum spectral range by period tuning. The use of confocal cavity design has brought a compact, all-solid-state configuration with an average output powers of idler up to similar to 200 m W. The maximum power of 277 mW was obtained at the wavelength of 3.35 mum.

Highly-Efficient Blue-Light Generation by Intracavity Frequency Doubling with LiB3O5

We have investigated the generation of highly-efficient blue light in critically type-I phase-matched LiB3O5 (LBO) with intracavity frequency doubling of diode-pumped Nd:YAG laser. A maximum output power of 502 mW at 473 nm blue light was obtained and the overall optical-to-optical efficiency is up to 11.2%. To the best of our knowledge, this is the highest conversion efficiency for 473 mm output using a diode pumped Nd:YAG laser through LBO.