Development of high power high brightness fiber coupled diode laser systems

Abstract

The improved wall-plug efficiency and minimal maintenance of diode laser systems over Nd:YAG and CO 2 lasers has been admired by many manufacturers. Until recently, most diode laser systems could not compete at highpower levels or with the same beam quality. Nuvonyx reports the design and initial development of a diode laser system that delivers 2000 W from a 600 µm core fiber with a 0.22 NA. This system is suitable as a standalone industrial direct diode laser system or as a multi-kilowatt fiber laser pump source. The development of a high brightness bar technology by Nuvonyx and its collaborators along with the use of polarization beam combining is the core of this laser system. Each emitter operates with a single lateral mode resulting in a high brightness bar that outputs up to 50 W. The wavelength of the laser is centered at 975 nm with a width of less than ± 3 nm. The demonstration of this laser system defines a clear path to scale this technology to 4000 W.

High-brightness fiber coupled diode laser systems

“…The high brightness bars reported here have been shown to exhibit a BPP of < 35 mm·mrad [5]. The dramatic improvement in beam quality does lower the conversion efficiency compared to broad-area devices.…”

Laser-based displays: a review

“…In order to get maximum efficiency, bundle dimensions should be as small as possible, which places restrictions on minimum jacketing and cladding thickness [101]. Design and fabrication of optical fiber couplers for diode arrays have been studied in the literature [102][103][104][105], and high-power diode lasers with fiber coupling are commercially available with optical powers up to 200 W [106]. However, if there is a mismatch be-tween the modes of the array emitters and the optical fiber, this approach is not efficient and results in reduced brightness.…”