Boxia Yan

Periodically poled self-frequency-doubling green laser fabricated from Nd:Mg:LiNbO 3 single crystal

Although a breakthrough in the fabrication of green laser diodes has occurred, the high costs associated with the difficulty of manufacture still present a great obstacle for its practical application. Another approach for producing a green laser, by combining a laser device and a nonlinear crystal, entails the fabrication of complex structures and exhibits unstable performance due to interface contact defects, thus limiting its application. In this work, we report the fabrication by domain engineering of high quality periodically poled LiNbO₃, co-doped with Nd³⁺ and Mg²⁺, which combines a laser medium and a high efficiency second harmonic conversion crystal into a single system that is designed to overcome the above problems. An 80 mW self-frequency doubling green laser was constructed for the first time from a periodically poled Nd:Mg:LiNbO₃ crystal of 16 mm in length. This crystal can be used for developing compact, stable, highly efficient mini-solid-state-lasers, which promise to have many applications in portable laser-based spectroscopy, photo-communications, terahertz wave generation, and laser displays.

High power green laser with PPMgLN intracavity doubled

The quasiphase matched PPMgLN crystal is used intracavity frequency doubled to obtain high power green laser, with a pump power of 20W at 808nm, 6.67W output power at 532nm is achieved.

A highly efficient 3.2 μm optical parametric oscillator pumped by a passively Q-switched Nd:YVO4 laser

We describe a compact all-solid-state singly resonant optical parametric oscillator (SRO) based on a Cr4+: YAG Q-switched Nd:YVO4 laser. The SRO is based on periodically poled MgO:LiNbO3 (PPMgLN) as the nonlinear material. By exploiting a 35 mm PPMgLN crystal, we achieved the SRO operation threshold at a pump power of only 140 mW. At 1.78 W of pump laser with a pulse width of 10 ns and a repetition of 50 kHz, 360 mW average power at 3.2 μm and a mid-infrared conversion efficiency of 20% were achieved.

Compact and efficient blue laser sheet for measurement

Compact and efficient blue laser sheet has important applications in the field of measurement, with laser diode end pumped Nd:YAG directly and LBO intracavity frequency doubling, a compact and efficient CW 473nm blue laser sheet composed of dual path liner blue laser is realized. At an incident pump power of 12.4W, up to 1.4W output power of the compound blue laser is achieved, the optical-to-optical conversion efficiency is as high as 11.3%.

Simultaneous three wavelength mid-IR laser by utilizing MgO:PPLN crystal

A multi-wavelength mid-infrared laser based on a multi-period doped MgO periodically poled lithium niobate (MgO:PPLN) was reported in this letter. The pump source was 1.064μm Q-switched Nd:YVO4 laser with a pulse repetition rate of 15kHz and pulse duration around 30ns. Three domain periods of 28.5μm, 29μm and 29.5μm in series were fabricated in a 2mm-thick z-cut MgO:PPLN, and the length of each domain period was 20mm. The extra-cavity singly resonant optical parametric oscillator had been demonstrated with a compact two-mirror cavity. Three idler wavelengths of 3825nm, 4004nm and 4165nm in the mid infrared were obtained at the same time, and the total output power was 139mW at 1.064μm pump power of 3.09W corresponding to optical-to-optical conversion efficiency of 4.5％ and the pump threshold was 1.04W for the 60mm-long MgO:PPLN.

Compact and efficient CW 473nm blue laser with LBO intracavity frequency doubling

With diode end pumped Nd:YAG directly and LBO intracavity frequency doubling, a compact, high efficient continuous wave blue laser at 473nm is realized. When the incident pump power reach 6.2W, 630mW maximum output power of blue laser at 473nm is achieved with 15mm long LBO, the optical-to-optical conversion efficiency is as high as 10.2%.

Compact intra-cavity frequency doubled line beam green laser by a laser diode array pumped

Compact, high power, and low-cost green laser light sources are needed in projection-related applications such as digital cinema, rear-projection television, simulators, and command and control stations. We report a LD array directly pumped intracavity SHG Nd:YVO4/PPMgLN laser without lens or waveguide in this letter. A compact 3.12 W green laser was demonstrated by intra-cavity frequency doubled using a PPMgLN bulk crystal by a 19-emitter LD array pumped(single bar), the conversion efficiency from input LD array was 9.2%. A line-beam output suitable for laser projectors was generated, which has the potential to be scalable to small volumes and low costs for laser projection displays.

High efficient CW 593.5nm yellow laser with PPMgLN intracavity sum-frequency mixing

With diode end pumped Nd:YVO4 and PPMgLN intracavity sum-frequency mixing, a compact, high efficient continuous wave yellow laser at 593.5nm is realized. At an incident pump power of 5.7W, up to 620 mW output power of yellow laser is achieved, the optical-to-optical conversion efficiency is as high as 10.9%.

Intracavity continuous-wave optical parametric oscillator tuning from 1.9μm to 2.4μm

We described a widely tunable intracavity continuous-wave singly resonant optical parametric oscillator (SRO) through a minimal laser diode end-pumped Nd:YVO4 laser. Laser source from 1.9μm to 2.4μm is obtained by temperature tuning of the 32.2μm period periodically poled MgO:LiNbO3(PPMgLN) crystal. The maximum power, 0.84W signal wave at 1.966μm and 0.56W idler wave at 2.319μm, are simultaneously obtained at 5.5 W of input diode power. The corresponding conversion efficiency are 15.2% and 10.2% respectively, so the whole efficiency is more than 25%. This allows the development of practical infrared cw SRO’s using compact, widely available, low-cost laser pump sources.

5W intracavity frequency-doubled green laser for laser projection

High power green laser has many applications such as high brightness laser projection and large screen laser theater. A compact and high power green-light source has been developed in diode-pumped solid-state laser based on MgO doped periodically poled LiNbO3 (MgO:PPLN). 5W fiber coupled green laser is achieved by dual path Nd:YVO4/MgO:PPLN intra-cacity frequency-doubled. Single green laser maximum power 2.8W at 532nm is obtained by a 5.5W LD pumped, MgO:PPLN dimensions is 5mm(width)×1mm(thickness)×2mm(length), and the optical to optical conversion efficiency is 51%. The second LD series connected with the one LD, the second path green laser is obtained using the same method. Then the second path light overlap with the first path by the reflection mirrors, then couple into the fiber with a focus mirror. Dual of LD, Nd:YVO4, MgO:PPLN are placed on the same heat sink using a TEC cooling, the operating temperature bandwidth is about 12°C and the stablity is 5% in 96h. A 50×50×17mm3 laser module which generated continuous-wave 5 W green light with high efficiency and width temperature range is demonstrated.