An Innovative All Solid-State Laser Source for Direct and Coherent Detection LIDAR

We introduce an innovative laser which brings inherently new capabilities to lidar that were not available with other coherent lidar laser sources. The unique design of this laser allows production of a greater range of pulse widths and energies than was previously obtainable from a single source. This 1.56 um eye-safe laser utilizes an intracavity Solid State Raman Shifter (SSRS) which is pumped by an energy-efficient Nd:YAG laser. The SSRS system utilizes a proven, power scalable design. SSRS provides an alternative to using 1.064 um Nd:YAG lasers with gaseous D2 Raman shifters. Important differences between SSRS and OPO's include the fact that SSRS devices do not require phase matching, have no acceptance product design margins, can have high quantum efficiencies, do not require the use of high quality pump beams to obtain efficient, diffraction limited output. In this proposed effort, we will develop efficient SSRS transmitter source suitable for both direct and coherent detection-mode lidars (a "dual-mode" lidar). Phase I of the program demonstrates frequency control of the SSRS system via injection seeding. Dual-detection mode lidars provide a means of optimizing system sensitivity in changing scenarios. Performance analyses for both direct and coherent detection will be performed. Incorporation of the new source into existing lidar systems will be addressed in Phase II.