Holographic Beam Combiner for High Power LADAR and Other Applications

Period of Performance: 11/27/2000 - 11/26/2002

$1.26MM

Phase 2 SBIR

Recipient Firm

Digital Optics Technologies, Inc.
64 Daly Dr. Ext
Stoughton, MA 02072
Principal Investigator

Abstract

The Holographic Beam Combiner, HBC, can be used to combine the output from many lasers into a singe-aperture, diffraction-limited beam. The HBC is based on the storage of multiple holographic gratings in the same spatial location. By using a material such as PDA, it is possible to combine up to 250 diode lasers, with and output intensity and birghtness 18 times as much as those of the individual lasers. The HBC will combine lasers with a wavelength resolution as small as .05nm, which is a factor of 30 better than alternative techniques fro beam combining using blazed gratings. This high wavelength resolution makes it possible to combine a large number of lasers withing a useful bandwidth, and is the key feature of our HBC. Our HBC has a wide range of applications of interest, including eyesafe ladars at 1550nm, erbium doped fiber amplifiers at 980nm, lasers printres at 830nm, and cancer treatment system at 660nm. The first one is of interest to all brances of the DOD, and the other three have obvious civilian applications. In Phase I, we deomonstrated a proof-of-principle HBC which combines three diode lasers, each with a power of 10mw. In order to establish firmly the commercial viability, it is necessary to demonstrate an HBC that will combine more lasers with higher input powers. During the first stage of Phase II, we will accomplish this goal by working out the technical issues and building a prototype HBC that combines 20 laser at 1550nm, with a combined power of 27W. The commitment of investment we have received already is expected to grwo substantially upon successful completion of this stage. This will enhance te degree of product sophistication, miniaturization and marketability we can achieve as we make the other three types of HBC(for printers, fiber amplifiers,a nd cancer therapy) during the second stage.