Patent ID: 7995638

Claim:
A laser system, comprising: a gain medium having a doping concentration and an absorption profile for absorption efficiency over a range of pump energy wavelengths and having a maximum absorption efficiency within the range, the gain medium having a first end, a second end and a length of 50 millimeters or more between the first and second ends; a source of pump energy having a wavelength at which the absorption efficiency is less than the maximum; and optics arranged to deliver the pump energy through the first end of the gain medium to propagate along the length of the gain medium; wherein the optics, pump energy wavelength, the length of the gain medium and the doping concentration of the gain medium establish absorption of greater than 80% of the pump energy delivered to the gain medium, and a 1/e absorption length of greater than one third the length of the gain medium, wherein the optics arranged to deliver the pump energy are adapted to image the pump energy at an image plane near the first end of the gain medium.