Spectral Beam Combining (SBC) of fiber lasers provides a simple, robust architecture for high brightness power scaling beyond the limit of a single fiber. We review recent progress in power scaling and describe what we believe is the highest power SBC fiber demonstration and largest number of fiber lasers combined to date. Here we report results on a fiber SBC system where we achieved > 30 kW by combining 96 individual fiber lasers into a single high brightness beam with a beam quality of M2 = 1.6 x 1.8. The potential for further power scaling at the system level is highlighted with examples of beam combinable fiber laser power scaling.
KEYWORDS: Infrared lasers, Fiber lasers, Optical amplifiers, Nonlinear crystals, High power lasers, Diode pumped solid state lasers, Laser applications, Frequency conversion, Infrared telescopes, Control systems
An air-cooled, light-weight, fiber-based, high power green laser has been prototyped. The system consists of an all-fibercoupled
IR pump laser at 1064 nm and a frequency-conversion module in a compact and flexible configuration. The IR
laser operates in QCW mode, with 10 MHz pulse repetition frequency and 3-5 ns pulse width, to generate sufficient peak
power for frequency doubling in the converter module. The IR laser can produce more than 200 W in a linearlypolarized
diffraction-limited output beam with high spectral brightness for frequency conversion. The converter module
has an input telescope and an oven with a nonlinear crystal to efficiently convert the 1064-nm IR fiber laser output to
532-nm green output. The IR laser and conversion module are connected via a stainless-steel protected delivery fiber for
optical beam delivery and an electrical cable harness for electrical power delivery and system control. The beam quality
of the 532 nm output remains near diffraction-limited, with M2<1.4. Up to 101 W of 532 nm output was demonstrated
and multi-hour runs were characterized at 75 W output. The weights of the IR laser package and doubler are 69 lbs and
14 lbs respectively. An overview of the system and full characterization results will be presented. Such compact, highbrightness
green laser sources are expected to enable various scientific, defense and industrial applications.
A 70-Watt green laser with M2<1.4 has been demonstrated. This green laser consists of an all-fiber-based IR pump laser
at 1064 nm and a frequency-conversion module in a compact and flexible configuration. The IR laser produces up to 150
Watts in a polarized diffraction-limited output beam with high spectral brightness for frequency conversion. The IR laser
is operating under QCW mode, e.g. 10 MHz with 3~5 ns pulse width or 700 MHz with 50 ps pulse width, to generate
sufficient peak power for frequency doubling in the converter module. The IR laser and conversion module are
connected via a 5-mm stainless-steel protected delivery fiber for optical beam delivery and an electrical cable harness for
electrical power delivery and system control. Both the IR laser and converter module are run through embedded software
that controls laser operations such as warm up and shut down. System overview and full characterization results will be
presented. Such a high power green laser with near diffraction-limited output in a compact configuration will enable
various scientific as well as industrial applications.
We present a novel approach to achieving both wavelength stabilization and
wavelength agility in high-power two-dimensional stacks of high-power laser diodes. This
approach utilizes volume Bragg gratings® with Bragg period that varies as a function of
position within the clear aperture of the element according to a periodic function with period
equal to the spacing between the laser diode bars within the stack. The Bragg period varies
linearly within each period so that translation of the volume Bragg grating element results in
simultaneous tuning of the wavelength of all the bars in the stack. As a result, the wavelength
of the stack is adjustable, stable and the emission line is narrowed to < 0.5 nm. This kind of
laser diode stacks is particularly suitable for pumping of gaseous media with very narrow
absorption lines, e.g. atomic vapors of rubidium, cesium, potassium etc.
Conference Committee Involvement (1)
Optical Components and Materials V
21 January 2008 | San Jose, California, United States
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