Laser oscillator and laser amplifier

摘要

A laser amplifier and/or oscillator comprise a gain medium including rare earth dopant in an host medium. Ions of the rate earth dopant has an energy level structure including a ground level and a pair of laser upper level and laser lower levels between which a stimulated transition is to be produced after production of a population inversion between the pair of laser upper and laser lower levels. A first exciting light source is coupled to the gain medium for introducing first exciting light to said gain medium to produce said population inversion. A second exciting light source is coupled to the gain medium for introducing second exciting light to the gain medium to raise the rare earth dopant ions from the ground level to the laser lower level.