Abstract

Microchip lasers (monolithic laser crystals with mirrors directly coated onto the plane-parallel end faces) are rugged devices that are easy to handle. If the crystal is short enough, single longitudinal mode operation can be achieved [1]. Under low pump power conditions, single transverse mode operation can also be obtained. If the pump power is increased, the transverse beam quality of these devices gradually deteriorates (especially in four level systems) and additional longitudinal modes start lasing. So the beneficial low power properties of microchips cannot be transferred to higher outputs by simply turning up the pump laser. Nd:YVO₄ is a well suited material for microchips due to its high pump absorption as well as high emission cross section and natural birefringence leading to linearly polarized output.

© 2000 IEEE