Transverse-pumping approach for a powerful single-mode Ti:sapphire laser for near infrared lidar applications

We present a new design of a transversely-pumped and powerful Ti:Sapphire laser, suitable for laser remote sensing in the near infrared (NIR) spectrum. Examining multiple pump configurations revealed that transversal pumping of Ti:Sapphire crystals with a Nd:YAG laser (532nm) from one or two sides, yields the maximum output power. Together with an optimized bow-tie
resonator setup, we were able to extract up to 3W (30mJ, 100Hz) of narrowband NIR laser emission from a
cuboid 50mm long Ti:Sapphire crystal. Beam quality and divergence were determined as $M_x^2 = 1.1$, $M_y^2= 1.7$, $\varphi_x = 0.5\mathrm{mrad}$, $\varphi_y = 0.8\mathrm{mrad}$. The spectral purity (seeded, $P_\mathrm{seed}\ge 170\mathrm{\mu W}$) was better than 99.8\%. Additionally, we show a two-wavelengths setup applicable to an atmospheric water vapor lidar. The principle performance of this theory of operation suggests a good chance of scalability towards significantly enhanced power of future Ti:Sapphire lasers.