Patent ID: 6933485
Filing Date: 2005-08-23
Classification: H01S

Abstract:
1. A stabilized radiation source comprising: a) radiation generating means for generating output radiation; b) radiation coupling means for coupling a portion of the output radiation into first and second optical paths; c) detecting means for detecting radiation transmitted through the first and second paths, and for generating first and second signals indicative of radiation power in the radiation transmitted through the first and second paths respectively; d) controlling means for controlling the generating means in response to the signals for stabilizing a wavelength and a radiation power of the output radiation to pre-selected power and wavelength values; e) the first path being operable to provide substantially unfiltered radiation to the detecting means; f) the second path including a filter for providing wavelength dependent filtered radiation to the detecting means, the filter having a transmission versus wavelength characteristic that decreases substantially linearly with radiation wavelength over a range of wavelengths in which the source is operable; and g) the controlling means being operable to control firstly the radiation power of the output radiation from the generating means so that a magnitude of the first signal is substantially equal to a first pre-selected magnitude for stabilizing said output radiation power to said pre-selected power value, and then operable to control the wavelength of the output radiation from the generating means so that a ratio of the second signal divided by the first signal is substantially equal in magnitude to a second pre-selected magnitude for stabilizing said output radiation wavelength to said pre-selected wavelength value.