Optical systems utilizing optical fibers transmitting high power signal and a method of operating such systems

摘要

An optical system comprises an optical fiber with gain producing core with an index of refraction n₁, surrounded by at least one cladding with an index of refraction n₂, said cladding including at least one index reduced area with an index of refraction n₂, such that n₁>n₂>n₂, the core propagating a signal at a spatial fundamental mode at a signal wavelength lambda₁ and at a power level sufficient to generate optical power at a wavelength lambda₂, where lambda₂>lambda₁, and the at least one index reduced area in combination with the core provide has at least one cut-off fundamental spatial mode wavelength lambda_C, and lambda₁C and lambda₂>lambda_C.