End pump laser, high power, pumped off peak

摘要

A laser system comprising: a gain medium (10) having a doping concentration and an absorption profile for absorption efficiency over a range of wavelengths of pump energy and having an effective absorption maximum within interval, having a first end, a second end and a length of 50 mm or more between the first (11) and second (12) ends the gain medium; a source of pumping energy (15; 105) having a wavelength at which the absorption efficiency is less than the maximum; and an optical (18, 22) arranged to supply the pump energy through the first end of the gain medium to propagate along the length of the gain medium; wherein the optical wavelength pump energy, the length of the gain medium and the doping concentration of the gain medium establish a greater than 80% of the pumping energy supplied to the gain medium absorption, and an absorption length 1 / e over a third of the length of the gain medium, wherein the optical arranged for supplying pumping energy being adapted to capture the image of the source of pumping energy in a plane nearby image the first end of the gain medium with a spot size, including arranged optical elements to provide a resonant cavity to provide a laser output adjusting mode resonant the spot size of the pump energy in the image plane cavity.