Monolithic Micro-Laser With KTP Ridge Waveguides for Injection Seeding High Power Lasers

This NASA Small Business Innovation Research Phase I project will develop a technique to greatly improve the direct coupling of a diode laser to an optical waveguide with embedded Bragg grating using no intermediate lenses. The key innovation proposed for this SBIR effort is a method for generating adiabatic tapers at the input end of optical waveguides in potassium titanyl phosphate (KTP). This innovation will significantly reduce the size, weight and complexity of the Bragg stabilized laser directly addressing NASA?s need for a compact, rugged, electrically efficient, tunable laser for injection seeding high power lasers for lidar. By injecting the output of the single-frequency, cw, seed laser source into a high power laser, such as a Q-switched Nd:YAG laser, longitudinal mode beating is eliminated that can cause random shot-to shot intensity fluctuations and excessive intra-cavity intensities that damage the internal optics in the laser cavity. The seed laser also enables high frequency stability and spectral purity from the high power host laser required by Doppler wind and atmospheric molecular lidar. A compact, robust seed laser is a critical component to extend the lifetime and achieve high frequency stability of high power laser systems used for lidar applications.