Abstract

Since Ho doped two-micrometer lasers operate in quasi-three level quantum systems, an effective heat release from the active region is required to depopulate the lower laser level and to achieve an efficient lasing. Reduction in diameter of the laser material volume is one of the effective ways to realize a high efficiency operation with axial pumping. Although glass materials have low thermal conductivity compared to laser crystals, they are, however, favorable for easy manufacturing of an optical fiber, which has very small diameter, resulting in the efficient heat release from the laser material. Moreover, good mode matching between the pump beam mode and the laser mode is easily obtainable even with the long fiber laser.

© 1995 IEEE