Systems, apparatus, and methods for producing ultra stable, single-frequency, single-transverse-mode coherent light in solid-state lasers

A laser system has a fiber cable, a pump enclosure connected to the fiber cable outside of the pump enclosure, and a laser-head enclosure connected to the fiber cable disposed outside of the laser-head enclosure. The pump enclosure houses a fiber-coupled laser diode configured to produce and convey pump light through the pump enclosure out to the fiber cable. The laser-head enclosure houses a crystal. The pump light, when produced by the laser diode, propagates out from the pump enclosure through the fiber cable into the laser-head enclosure and into the crystal. The crystal produces a laser beam in response to the pump light. The integrated fiber of the laser diode, the fiber cable, and internal fiber of the laser-head enclosure, through which the pump light propagates, may be single-mode fibers, to achieve superior laser system performance with lower frequency and intensity noise than pumping through multimode fibers.