Two-Stage Brightness Converter

Abstract

There is provided a two-stage brightness converter. A first brightness conversion stage has a laser cavity having a first optical waveguide doped with an active ion defining a first optical band with optical absorption, a second optical band with optical absorption and optical gain, and a third optical band with optical gain. The first laser cavity is pumped with a pump power having a wavelength in the first optical band to generate an intermediate optical signal in the second optical band. A second brightness conversion stage which is in cascade with the first brightness conversion stage comprises a second optical waveguide doped with the same active ion. The second brightness conversion stage is pumped with the intermediate optical signal to obtain a high brightness optical signal in the third optical band.

Description

[0001] Cross References to Related Applications

[0002] This application claims priority to US Provisional Application 61 / 146,812, filed January 23, 2009, the specification of which is incorporated herein by reference. technical field

[0003] This specification relates to the generation of optical signals, and more specifically to brightness transformation. Background technique

[0004] Today, fiber lasers are the most powerful solid-state laser technology due to their compactness, reliability, operating efficiency and their high output power levels. Fiber lasers can be viewed as single-stage brightness converters.

[0005] One approach to designing brightness converters uses laser cavities (see e.g. "1.3kW Yb-doped fiber laser with excellent beam quality" by A. Liem et al. Proc. of CLEO 2004, CPDD2, Vol.2, pp.1067-1068 , (2004)). In such a brightness converter, a large number of multimode pump diodes are coupled into a rare earth-doped double-clad fiber (DCOF) using a ...

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