2.1 µm Compact Laser with Fiber Launched Output for Urological Applications

For some urological applications such as lithotripsy and Benign Prostatic Hyperplasia (BPH) treatment, high average power and high pulse energy laser emission in the 2 µm spectral region is required. Often, this requires the usage of multiple laser resonators combined to overcome the thermal effects of the CTH:YAG gain media. Beam combining methods can be complicated and difficult to align. Our novel beam combining method, with the use of several enabling technologies, results in a physically and optically compact design capable of reaching high average power. We report on the output of a beam combined laser with 4 independently operating CTH:YAG resonators lasing on the 2.13 µm transition. Each resonator produced approximately 4 J at a repetition rate of 10 Hz, resulting in a combined output of more than 4 J at 40 Hz. We have demonstrated the output of beam combined resonators resulting in an output greater than 120 W through a 600 µm fiber at a 40 Hz repetition rate. We have also demonstrated the ability to launch a laser beam with output power of approximately 60 W through a 200 µm fiber.
