Patent ID: 6101211
Filing Date: 2000-08-08
Classification: H01S

Abstract:
A narrow band laser apparatus comprising:a laser generating section having laser activity for generating a laser beam;bandwidth narrowing means arranged at one end of the laser generating section on an optical axis of the laser beam generated by the laser generating section, for narrowing bandwidth of the laser beam by means of at least one angle-dispersion wavelength selection element, and folding back the laser beam that has been narrowed in bandwidth to emit the laser beam to the laser generating section;beam folding-back means arranged at another end of the laser generating section on the optical axis of the laser beam generated by the laser generating section, for folding-back the laser beam that is input, and reflecting it to the laser generating section; anda laser beam branching unit arranged between the laser generating section and the bandwidth narrowing means, having a reflective region and an optically transparent region that spatially separate the laser beam that is input from the laser generating section with respect to a sectional region of the laser beam for transmitting part of the laser beam that is input from the laser generating section through the optically transparent region to input it to the bandwidth narrowing means and deflecting a remaining part of the laser beam through the reflective region in a direction to avoid inputting the remaining part again to the laser generating section to output it as an output beam.