AFRL Advanced Electric Lasers Branch: Construction and Upgrade of a 50- watt Facility-Class Sodium Guidestar Pump Laser

摘要

The development of a reliable and effective laser source for pumping mesospheric sodium to generate an artificial guidestar has been well documented. From the early achievements with 589nm high-power dye lasers at the Keck and Lick observatories to the ground-breaking 50W CW FASOR (Frequency Addition Source of Optical Radiation) Guidestar at the Air Force's Starfire Optical Range (SOR), there has been intense interest in this technology from both the academic and military communities. Beginning in the fall of 2008, the Air Force Research Laboratory's Advanced Electric Lasers Branch began a project to build, test, verify and deliver an upgraded version of the SOR FASOR for use at the AF Maui Optical Station (AMOS) in the summer of 2010. This device, called 'FASOR-X' will be similar in design to the existing SOR device and produce 50W of diffraction limited, linearly polarized narrow linewidth 589nm light by combining the output of two injection-locked Nd:YAG ring lasers (operating at 1064nm and 1319nm) using resonant sum-frequency generation in a lithium triborate crystal (LBO). This upgraded system will include features such as modularized sub-components, embedded control electronics, and a simplified cooling system. The first portion of this upgrade project is to test and build the two injection laser cavities while validating the improved control mechanisms FASOR-X will employ. In parallel with this effort, the technical plans for the modularization and re-packaging of the FASOR will be finalized and coordinated with the staff at Maui. This paper summarizes the results of these efforts to date and provides updates on the AMOS FASOR-X status. Additionally AFRL plans for next-generation guidestar pump sources will be discussed.