Z. D. Gao

Monolithic red-green-blue laser light source based on cascaded wavelength conversion in periodically poled stoichiometric lithium tantalate

A compact, pulsed, red, green, and blue laser source based on cascaded quasi-phase-matched wavelength conversion in two periodic superlattices set in tandem in a single stoichiometric LiTaO3 crystal and pumped by a laser source at 532nm is reported. The white light equivalent flux obtained was 80lmper1W input with a green to white light power conversion efficiency of >30%. Unity power conversion is feasible in this monolithic approach.A compact, pulsed, red, green, and blue laser source based on cascaded quasi-phase-matched wavelength conversion in two periodic superlattices set in tandem in a single stoichiometric LiTaO3 crystal and pumped by a laser source at 532nm is reported. The white light equivalent flux obtained was 80lmper1W input with a green to white light power conversion efficiency of >30%. Unity power conversion is feasible in this monolithic approach.

High-power red-green-blue laser light source based on intermittent oscillating dual-wavelength Nd:YAG laser with a cascaded LiTaO3 superlattice.

We demonstrate a high-power red-green-blue laser source based on the quasi-phase-matching and intermittent oscillating dual-wavelength laser technique. A cascaded LiTaO3 superlattice was used to achieve the generation of red light at 660 nm, green light at 532 nm, and blue light at 440 nm to obtain the output of red-green-blue laser light from a diode-side-pumped Q-switched intermittent oscillating dual-wavelength Nd:YAG laser. The average output power of red-green-blue of 1.01 W was achieved under the total fundamental power of 5.1 W, which corresponds to the conversion efficiency of 20%.

Efficient periodically poled stoichiometric lithium tantalate optical parametric oscillator for the visible to near-infrared region

A compact, efficient optical parametric oscillator (OPO) for the visible to near-infrared region based on periodically poled stoichiometric lithium tantalate pumped by a frequency-doubled multikilohertz Q-switched Nd:YAG laser is demonstrated. Up to 61% photon conversion with a 71% slope efficiency for photon conversion from 532 nm to the signal radiation was measured. We observed that the efficient conversion diminished the potential for photorefractive damage induced by the 532 nm radiation in the crystal and made sustained operation of the OPO device possible.

530-mW quasi-white-light generation using all-solid-state laser technique

We report a quasi-white-light laser, which was generated by an all-solid-state laser technique. The approach is to use a cascaded optical superlattice in a LiTaO3 crystal to directly frequency double and triple a diode-pumped, Q-switched dual-wavelength Nd:YVO4 laser. Three primary color lights, red at 671nm, green at 532nm, and blue at 447nm, were simultaneously generated in a proper proportion, forming a quasicontinuous, quasi-white-light laser with a maximum output power of 530mW under a pump power of 18W. From the result, a more effective quasi-white-light output can be anticipated if the superlattice is fabricated in a stoichiometric LiTaO3 crystal and the double resonant technique is further optimized.

Study of optical elastic scattering in a quasiperiodically poled LiTaO3 crystal

In this letter we report the experimental result on the study of light scattering in a one-dimensional quasiperiodically poled LiTaO3 crystal. The infrared scattering signal in the crystal was upconverted into visible band by sum frequency with incident light, forming a set of coaxial conical second harmonic beam with a quasiperiodic ratio at the radius. The quasi-phase-matching significantly enhanced such a nonlinear interaction. The angular distribution of scattering light in crystal was extracted from the experimental result. This reveals a possible application of quasiperiodic structure on the study of light scattering.

Green-pumped high-power optical parametric oscillator based on periodically poled MgO-doped stoichiometric LiTaO3.

A high-power 532 nm-pumped multikilohertz nanosecond optical parametric oscillator using a periodically poled 1.0 mol.% MgO-doped stoichiometric lithium tantalate crystal that could be operated from room temperature to 200 degrees C without damage is reported. A broad continuous tuning range from 855 to 1410 nm was achieved within a single domain period. Efficient operation of high peak power and watt level average power with a power conversion of 62.5% was measured. These results show that a high-resolution high average power visible tunable source can be realized.

Multiple-channel mid-infrared optical parametric oscillator in periodically poled MgO: LiNbO3

We report a compact all-solid-state mid-infrared optical parametric oscillator with wide tunability using periodically poled 5 mol % MgO-doped LiNbO3 with a multiple-channel structure design and pumped by a compact diode-pump solid-state laser operating at 1.064 μm. Wide tunability from 1.44 to 1.58 μm at the signal beam wavelength and from 3.28 to 4.11 μm at the idler beam wavelength was achieved by both varying the temperature and translating the crystal through the resonator and the pump beam with no realignment required. The tuning performance and its related factors were analyzed, and at the same time the output performance as well as the effect of mid-infrared absorption of idler beam was investigated.

All-solid-state red and green laser by temperature tuning

In this paper, we report how to realize an all-solid-state laser with an efficient dual-wavelength red and green light output by temperature tuning. This laser is constructed with a nonlinear crystal and a diode-pumped, Q-switched Nd?:?YVO4 laser as the fundamental source with the dual-resonance wavelengths at 1342 and 1064?nm. The nonlinear crystal is a specially designed superlattice that is able to achieve quasi-phase-matched frequency doubling of 1342 and 1064?nm at two phase-matching temperatures. Using this scheme, 520?mW red light and 332?mW green light are generated at 118.5?C and 113?C, respectively, from two moderate fundamental powers with an efficiency of around 25?30%. The results provide a possible scheme for obtaining multi-wavelength output from a mono-laser by only adjusting the operating temperature.

Determination of the refractive index dispersion using multi-wavelength second-harmonic generation in an aperiodic LiTaO3 superlattice

Multi-wavelength second-harmonic generation in an aperiodic poled LiTaO3 superlattice was studied. By fitting the measured data of phase-matching wavelengths and temperatures, the temperature-dependent Sellmeier equation of the LiTaO3 crystal has been determined. This work provides a new method to measure the refractive index of the nonlinear crystal and its dispersion and therefore, is of benefit to the study of the quasi-phase-matching technique.

High-power red-green-blue all solid state laser based on an optical superlattice

A stable red, green and blue output was obtained by frequency doubling and tripling an alternate resonant dual-wavelength Q-switched Nd:YAG laser with an optical superlattice in a LiTaO3 crystal as a frequency converter.