Sandford, S. P. | Search NASA

NASA NTRS1997

Angular Alignment Testing of Laser Mirror Mounts Under Temperature Cycling

A number of commercial and custom-built laser mirror mounts were tested for angular alignment sensitivity during temperature cycling from room temperature (20 C) to 40 C. A Nd:YAG laser beam was reflected off a mirror that was held by the mount under test and was directed to a position-sensitive detector. Horizontal and vertical movement of the reflected beam was recorded, and the angular movement, as a function of temperature (coefficient of thermal tilt (CTT)) was calculated from these data. In addition, the amount of hysteresis in the movement after cycling from room temperature to 40 C and back was determined. All commercial mounts showed greater angular movement than the simpler National Aeronautics and Space Administration Lidar Atmospheric Sensing Experiment (NASA LASE) custom mirror mounts.

Bullock, K. T.↗

NASA NTRS1992

Progress toward ultra-stable lasers for use in space

This is a summary of a research project that has come to be known as SUNLITE, initially standing for Stanford University - NASA laser in space technology experiment. It involves scientists from the NASA Langley Research Center (LaRC), Stanford University, the National Institute of Standards and Technology (NIST), and the Joint Institute for Laboratory Astrophysics (JILA), and a growing number of other institutions. The long range objective of the SUNLITE effort is to examine the fundamental linewidth and frequency stability limits of an actively stabilized laser oscillator in the microgravity and vibration-free environment of space. The ground-based SUNLITE activities supporting that objective will develop a space-qualified, self-contained and completely automated terahertz oscillator stabilized to a linewidth of less than 3 Hz, along with a measurement system capable of determining laser linewidth to one part in 10(exp 16). The purpose of this paper is to discuss the critical technologies needed to place stabilized lasers in space and to describe the progress made by the SUNLITE project to develop these technologies.

Buoncristiani, A. M.↗