New generation of eye safe military applications such as range finding, short range illumination and friend or foe
identification have started to use the 1550nm wavelength region. This was encouraged by the advent of diode lasers
efficient enough to approach the output power of shorter wavelength, 850nm and 905nm devices. This paper will review
the actual performance and technologies of various commercially available 1550nm pulsed laser diodes. The
performance and reliability of a new high brightness 1550nm semiconductor laser diode are disclosed and compared.
Peak power of up to 35 Watts is achieved out of a single junction 350 micron stripe laser. Similarly, peak power in
excess of 20W is achieved with a 180 micron stripe laser. This represents an optical power density of 11.1M W/cm<sup>2</sup>.
Other key advantages of this new laser are a fast axis FWHM divergence of 25 degrees and less than a 10mRad
divergence after fast axis collimation. The new diode technology will be explained in some detail covering aspects of
design, fabrication and adaptation to meet its final target performances. A description of the optimization of chip
dimensions and laser packaging is also undertaken. Finally, various ideas are offered to further improve the laser
efficiency and power.
The 1550nm wavelength region is critical to the development of next generation eye safe military applications such as
range finding and friend or foe identification (FOE). So far the relatively low laser external efficiency was a strong
limiting factor favoring shorter wavelength diode lasers. We report on the development of a new monolithic multiple
junction pulsed laser diode offering an external efficiency of more than one Watt per Amp with high brightness. Peak
optical output power of more than 37 Watts has been achieved from a single multi-junction diode laser. Divergence is
narrow with less than 35 degrees (FWHM) in the fast axis direction. Starting from an AlGaInAs quantum well laser
structure, we show the criticality of the design of InP based tunnel junctions to the growth of the three layer epitaxial
monolithic laser. We then report on trenches employed to confine carriers under the contacting stripe and on growth
strategies used to decouple the multiple light sources resulting from the multi-junction design. A full set of
characterization data is presented concluding with a discussion on performance limitations and their potential causes.
We describe recent advancements in laser light scattering hardware including intelligent single card correlators, active quench/active reset avalanche photodiodes, laser diodes, and fiber optics which were used by or developed for a NASA Advanced Technology Development program. We then preview a space shuttle experiment which will employ aspects of these hardware developments.