Two-micron semiconductor disk lasers achieve higher powers

ner High-quality semiconductor disk lasers at wavelengths above 2µm promise new applications as they produce powers as high as 5W. There is an increasing demand for lasers with emission wave-lengths at or above 2µm for long-range sensing, such as light detection and ranging (LIDAR) for surveying land, or free-space broadband communication by means of a modulated beam of light transmitted through the atmosphere. Other potential uses of long-wavelength lasers are security-related, or medical ap-plications such as laser surgery. Most of these require both a high output power and a very-high-quality laser beam. Classi-cal semiconductor diode lasers can reach high output powers at this wavelength,1 but fail to deliver the quality of beam neces-sary for e.g. a small focus spot or long transmission range. An optically-pumped semiconductor disk laser (OPSDL), als