Pingxue Li

A widely tunable QCW Ti:sapphire laser and its frequency doubling with LBO crystal

We report an all-solid-state QCW (quasi-continuous-wave) tunable Ti:sapphire laser system from 697nm to 942nm, which was pumped by an intra-cavity frequency doubling Nd:YAG laser at 532nm. Under the pump power of 18W at 532nm with the repetition rate of 3.9kHz, the average output power of 3.5W at 795nm with an optical conversion efficiency of 20% was yielded. Through extra-cavity frequency doubling with the nonlinear crystal LBO (LiB3OWe report an all-solid-state QCW (quasi-continuous-wave) tunable Ti:sapphire laser system from 697nm to 942nm, which was pumped by an intra-cavity frequency doubling Nd:YAG laser at 532nm. Under the pump power of 18W at 532nm with the repetition rate of 3.9kHz, the average output power of 3.5W at 795nm with an optical conversion efficiency of 20% was yielded. Through extra-cavity frequency doubling with the nonlinear crystal LBO (LiB3O5), cut for critical type I phase matching (θ=90°, φ=33.2°) at room temperature, tunable second-harmonic generation (SHG) from 350nm to 465nm was achieved. Through the design of the scan and control system, the whole laser system can be used to expose the sensitive material under the controlling of computer.

A Q-Switched 980 nm Yb-Doped Single-Mode Fiber Amplifier and Its Frequency Doubling

In this paper, a single-mode Q-switched 980 nm Yb-doped fiber amplifier were studied experimentally. In the experiment, we used a 980 nm acousto-optics (AO) Q-switched Yb-doped single-mode fiber laser as the seed source, which generated an average output power of 73 mW at 980 nm with the pulse width of 10 ns at repetition frequency of 16 kHz. Then, another single-mode Yb-doped fiber pumped by a cw 946 nm Nd:YAG laser composed the fiber amplifier. As a result, the 980 nm amplified light with 150 mW average output power was generated. Through frequency doubling the 980 nm laser with a BIBO crystal, an average output power of 8 mW of pulsed blue-green laser at 490 nm was generated.

A Quasi-Three-Level Acousto-Optics (AO) Q-Switched Yb-Doped Double Clad Photonic Crystal Fiber Laser

We demonstrate a acousto-optics (AO) Q-switched 980 nm Yb-doped photonic crystal fiber (PCF) laser, which generated an average output power of 731 mW from single end of the fiber when the fiber length was 30 cm. The laser pulse of 40 ns and pulse repetition frequency of 6 kHz was detected. This Q-switched 980 nm PCF laser reached a peak power of 3 kW. The linewidth of the laser was 3.5 nm arranging from 977 nm to 980.5 nm. A fiber coupled diode laser with the center wavelength of 915 nm was used as the pump source for the 980 nm pulsed PCF laser.

High power picosecond amplification in a large-core double-clad Yb-doped fiber

We report on the amplification of 21ps pulses up to 10W average output power in both a conventional ytterbium-doped large-core double-clad fiber and photonic crystal fiber (PCF). The picosecond fiber amplifier system consists of a mode-locked Nd:YVO4 oscillator and a diode-pumped double-clad large-core ytterbium-doped fiber. a passively mode-locked (SESAM) Nd:YVO4 oscillator is used as the picosecond seed source, which has repetition rate of 93 MHz, pulse duration as short as 19.2 ps at 1064 nm and an average power of 380 mW. At first, conventional double clad fiber is used as the amplifier medium, which has an inner cladding diameter of 250 μm and the active core diameter of 30 μm. The absorption coefficient of this fiber is as high as 9 dB/m at 976 nm. Secondly, PCF with an inner cladding diameter of 200 μm, the active core diameter of 40 μm is chosen for the amplifier with the same absorption coefficient as the conventional double clad fiber. For these two kinds of fiber amplifiers, both more than 10 W amplified output power have been achieved. Since lager mode area double clad ytterbium-doped fiber and photonic crystal fiber have been chosen in the amplifier, which would lead to a reduced nonlinearity, spectral broadening due to SPM is extensively suppressed.

The experimental study of a CW 980nm double-clad photonic crystal fiber laser

In this paper, we report on a CW 980 nm double clad photonic crystal fiber laser pumped by the CW 915 nm diode laser. The photonic crystal fiber used in the experiment has a core diameter of 40 μm, inner clad of 200 μm, an absorption coefficient of about 3 dB/m at 915 nm. The fiber length is 40 cm. In the single-end output experiment, an output power of 1.2 W with a slope efficiency of 15% has been achieved. To the best of our knowledge, it was the first time for the 980 nm Yb-doped fiber laser by using the flexile large-mode-area double-clad photonic crystal fiber.

CW and Q-switched Yb-doped single-mode fiber lasers at 980nm and their frequency doubling with BIBO

In this paper, we demonstrated a single-mode Yb-doped fiber laser at 980nm pumped by cw and Q-switched 946u2005nm Nd:YAG laser. The Yb-doped fiber laser adopting two 0° fiber ends as cavity mirrors generated a cw output power of 1.32u2005W at 980u2005nm with the slope efficiency of 75.3%. The corresponding optical conversion efficiency was 66% from the incident pump power at 946u2005nm to the laser power at 980u2005nm. Through frequency doubling with BIBO crystal, a total output power of 18u2005mW at 490.8u2005nm was obtained. Simultaneously, we produced a 980nm Yb-doped single-mode pulse fiber laser with the FWHM of 10u2005ns at repetition frequency of 16u2005kHz pumped by an acousto-optics Q-switched Nd:YAG laser at 946u2005nm. The pulsed fiber laser generated a total average power of 95u2005mW at 980u2005nm.