Laser Test Stand for Silicon Detectors

To achieve a better precision in the position resolution to characterze responses of silicon detectors to high-energy particles, a laser test stand was designed and constructed. The infrared laser ($\lambda=1060$ nm) with a focused spot of 25 microns in diameter mimics high-energy particles to generates signals in Silicon detectors under test. The injection point of the laser on the Silicon sensors is controlled by a set of precision motors, allowing for precise movement at minimum of 3 micron steps in three dimensions. This talk will discuss the design and operation of the laser test stand, as well as results obtained for prototype modules of STAR Foward Silicon Tracker.