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Green Diode Lasers (480-550 nm Spectral Regime)

Description:

TECHNOLOGY AREA(S): Sensors

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 5.4.c.(8) of the solicitation.

OBJECTIVE: To develop longer wavelength visible diode lasers primarily aimed at green color wavelengths from 480 nm – 550 nm.

DESCRIPTION: Laser diodes are of significant interest to both the commercial and military sectors because of the compactness and potential high efficiency of their emission. Depending on their cavity designs, varying linewidths and output powers are possible for various applications. However, due to a variety of issues involving the growth of high quality epitaxial semiconductor materials in the green color optical bandgap regime (480 – 550 nm), green laser diodes have yet to be commercialized in the United States. Although much progress was reported after the DARPA VIGIL program [1-2], commercialization efforts shifted to overseas, and the wavelengths were primarily limited to 520 nm or less [3]. However, laser diodes spanning out to even longer wavelengths are of interest for applications in frequency doubling for UV laser emission in the 260 – 275 nm region [4]. The pursuit of such challenges has been studied with semipolar GaN substrates to minimize defect formation and increase the critical thickness for longer wavelength emission. Other approaches may be possible too using alloys of ZnO [5].

PHASE I: Study the growth, doping, and design of green laser heterostructures, particularly emphasizing the active region toward longer wavelengths than commercially available (520 nm – 550 nm). Feasibility analysis with supporting experimental data showing laser designs with emission powers of 100 mW at 480 nm and several mW or more across the green emission spectrum.

PHASE II: Pursue the full implementation of the ideas and initial growth runs done during phase I. Pursue growth of semiconductor alloys (likely InGaN with semipolar GaN substrates) with improved material quality and emission properties out to 550 nm. Goals would include 1 W emission power at 480 nm and 100 mW at 520 nm with at least 10 mW or more (continuous wave at room temperature) at 550 nm. Begin to evaluate reliability at various wavelengths and determine material related limitations and causes.

PHASE III DUAL USE APPLICATIONS: Continue to evaluate reliability across the wavelength spectrum to assess power output levels available and various applications of interest to military and civilian markets. Potential civilian applications include pico-projectors for miniature projection displays as well as potential use in head-lights and other lighting uses. The military uses could be several that include chemical and biological sensors that include integration with photonics integrated circuits or second harmonic generation for UV lasers from 240 – 275 nm, and the uses of UV lasers in a compact form factor are numerous from sensing to water purification to various forms of optical communications.

REFERENCES:

    • James W. Raring, et. al., “High-Efficiency Blue and True-Green-Emitting Laser Diodes Based on Non-c-Plane Oriented GaN Substrates,” Applied Physics Express, 3, 112101, 2010.

 

    • J. W. Raring, et. al, “State-of-the-art continuous wave InGaN laser diodes in the violet, blue, and green wavelength regimes” Proc. SPIE 7686,76860, 2010.

 

    • Y. Zhao, et. al., “Indium Incorporation and emission properties of nonpolar and semipolar InGaN quantum wells,” Appl. Phys. Lett., 100, 201108, 2012.

 

    • R. Kirste, et. al., “Properties of AlN based lateral polarity structures,” Phys. Status Solidi C, 1-4, 2014.

 

  • K. A. Bulashevich, I. Yu. Evstratov, and S. Yu. Karpov, “Hybrid ZnO/III-nitride light emitting diodes: modelling analysis of operation,” Phys. Stat. Solidi A, 204, 1, 241, 2007.

KEYWORDS: green laser diodes, semi-polar gallium nitride substrate, non-polar gallium nitride substrate, zinc oxide alloy

  • TPOC-1: Dr. Michael Gerhold
  • Phone: 919-549-4357
  • Email: michael.d.gerhold.civ@mail.mil
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