RESUMEN
We fabricate a novel, to the best of our knowledge, acousto-optic Q switch in the 3-micron wavelength range using a longitudinal acoustic mode in a lithium niobate (LiNbO3) crystal. The device is designed based on properties of the crystallographic structure and material to obtain a high diffraction efficiency close to the theoretical prediction. The effectiveness of the device is verified by application in an Er,Cr:YSGG laser at 2.79â µm. The maximum diffraction efficiency reached 57% at the radio frequency of 40.68â MHz. At the repetition rate of 50â Hz, the maximum pulse energy was 17.6 mJ and the corresponding pulse width was 55.2â ns. The effectiveness of bulk LiNbO3 as an acousto-optic Q switch is verified for the first time.
RESUMEN
We report on a high-peak-power electro-optically Q-switched laser emitting a near-diffraction-limited beam profile at 1064 nm by using a gradient-doped Nd:YAG crystal. The gradient-doped crystal features a unique combination of a reduced thermal lens effect through effectively spreading the heat load distribution within its volume. Its performance is compared with those of Nd:YAG crystals with uniform volume doping distribution operating in the Q-switched regime with the same laser configuration, demonstrating the higher average and peak power achievable with the gradient-doped crystal. The maximum average output power amounts to 6.9 W at a pulse repetition rate of 2 kHz, which corresponds to a maximum peak power of â¼585kW. Compared to homogeneous dopant crystals, the slope efficiency and average output power increased by 30.8% and 21.1%, respectively.