Patent ID: 7423803

Claim:
A 1-μm amplified spontaneous emission (ASE) source, comprising: An optical gain fiber of 10-150 cm in length having a proximal section with a proximal end and a distal section with a distal end including, At least one cladding layer formed from phosphate glass; and A core formed from phosphate glass and doped with 0.5-20 weight % of ytterbium-oxide; and A pump source that injects optical energy into the proximal end of the first optical gain fiber to excite the ytterbium oxide ions in the core and provide gain in said proximal section to build-up backward and forward ASE in the proximal section of the gain fiber and to provide loss in said distal section, wherein said pump source and optical gain fiber are configured for backward propagation of said backward ASE through the proximal end of the fiber for with a full width half maximum (FWHM) spectral emission bandwidth of at least 10 nm that includes 1020 nm and for forward propagation of said forward ASE through the distal end of the fiber to attenuate the forward ASE; and a section of angle cleaved fiber at the distal end of the gain fiber that allows the attenuated forward ASE to exit the gain fiber without reflecting power back into the gain fiber.