Patent ID: 7907266
Filing Date: 2011-03-15
Classification: G01J

Abstract:
1. A radiometer for calibrating collimated pulsed laser sources comprising: a) a lens barrel configured to receive a laser beam having a pulse and power generated by a collimated pulse laser; b) said lens barrel including first and second piano convex lenses disposed in front of an aspheric lens, said lenses oriented and spaced apart so as to minimize a spot size of a collimated laser beam at a selectable one of two points in space behind the aspheric lens; c) a detector module including an avalanche photo diode which receives said laser beam after passing through said three lenses, a detector circuit and a heater ring having a temperature controlled by a temperature control circuit, said temperature control circuit for maintaining said diode at a constant sensitivity for use as a calibration standard; d) said detector module mounted on a translation stage for positioning said avalanche photo diode at one of two predetermined positions based on a wavelength of a laser beam from a source being calibrated; e) a signal routing module coupled to said detector circuit for receiving an output generated by said detector circuit, said output being a voltage corresponding to said pulse and power, said routing module for routing and converting said voltage for display on an oscilloscope.