Tingting Lu

1047nm 270mJ all solid state diode pumped MOPA at 50 Hz

A diode-pumped nanosecond Master Oscillator Power Amplifier (MOPA) system based on Nd:YLF crystal slabs has been demonstrated. The seed pulses with pulse duration of 11 ns were generated in an EO Q-switched Nd:YLF laser, with single pulse energy of 10 mJ. The 1047 nm signal pulses were amplified in a double-pass amplification system. Maximum output pulse energy of 270 mJ at a repetition rate of 50 Hz has been achieved with effective optical-to-optical efficiency of 14.5%.

160mJ and 9ns electro-optics Q-switched conductively cooled 1047nm Nd:YLF laser

A compact diode side-pumped conductively cooled 1047 nm Nd:YLF slab laser with high energy and short pulse width is developed. Through ray tracing method, we design a home-made pump module to homogenize the pump intensity. Based on the Possion equation, a thermal conduct model of side-pump laser is established. The temperature distribution in laser crystal is obtained, and the thermal lens is caculated. With the absorbed pump energy of 818 mJ, the maximum output energy of 228 mJ is achieved in free-running mode. At a repetition rate of 50 Hz, 160 mJ, 9 ns 1047 nm infrared light is obtained under the maximum absorbed pump energy, and the slope efficiency is 27.8%.

Comparison of high repetition rate Q-switched 355nm ultraviolet lasers with EOM and AOM

Two kinds of Q-switched ultraviolet lasers using an acousto-optic modulator and an electro-optic modulator in the same cavity structure are demonstrated, with type I phase-matched LBO as second harmonic generation crystal and type II phase-matched LBO as third harmonic generation crystal. For acousto-optic Q-switched UV laser，a maximum average power of 6.3W with the shortest pulse width of 12 ns was obtained at the repetition rate of 22 kHz when the pump power reached 52.4 W. The optical conversion efficiency was up to 12%. Then we used a La3Ga5SiO14 crystal electro-optic modulator to replace the acousto-optic modulator. The 1.29W output power at 355nm wavelength was obtained at the repetition rate of 10 kHz when the pump power was increased to 20.4W, and the UV laser pulse width was as short as 9.6ns.The optical conversion efficiency was up to 6.3%.

High efficient Q-switched Nd:YLF laser operating at 523.5nm with near-diffraction-limited beam quality

An efficient and compact green laser at 523.5 nm was generated by intracavity frequency doubling of a diode end-pumped conductively cooled Q-switched Nd:YLF laser at 1047 nm. With an incident pump pulse energy of 28.6 mJ at 250 Hz repetition rate, pulse energy of 8 mJ was obtained with a pulse width of 10 ns, corresponding to an optical– optical conversion efficiency of 28%. The beam quality factors were Mx 2 =1.35,My 2 =1.21.