Upconversion fiber laser

Abstract

An upconversion fiber laser uses a pump source which may be another fiber laser, such as a high power, diode-laser-pumped, fiber laser. The upconversion fiber laser includes an optical fiber whose core region is doped with an active lasing ionic species capable when optically pumped of undergoing upconversion excitation, such as certain rare earth ionic species, and which is embedded in a cladding of the optical fiber. Use of a fiber pump laser can improve coupling of pump light into the optical fiber, thereby achieving higher pump intensities in the core region and improved upconversion efficiency. The upconversion fiber laser's resonant laser cavity is defined by feedback means which can include at least one reflective grating formed in the optical fiber, as well as a reflective end face of the optical fiber. Any portion of the optical fiber that lies outside of the resonant laser cavity, such as any portion beyond the integral reflective grating, may act as an optical power amplifier for the upconverted laser output. The disclosure includes other embodiments in which pump brightness can be further increased with multiple pump sources.

Dependencies are inferred from the claim text.