SITIS Topic Details |
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| Proposals Accepted: | |
| Program: | STTR |
| Topic Number: | AF10-BT23 (AirForce) |
| Title: | Beam Control for Optical Phased Array Transceivers | Research & Technical Areas: | Sensors |
| Objective: | Design, develop, and demonstrate a novel beam control approach for optical phased array weapons.
| Description: | Optical phased arrays show great promise in aircraft-based directed energy weapons. By employing a number of independent subapertures instead of a monolithic telescope, phased arrays can be compact, conformal and lightweight. Such systems combine the effects of several lasers that are individually lower in power than the large, heavy and toxic solutions currently in use.
Phased arrays were demonstrated by the US Air Force in the late 1980s but were abandoned due to the tight tolerances required by beam-combining optics. A new approach has been developed that replaces such optics with digital processes. This solution uses interferometry to capture and record the complex field at each subaperture. This information is then stitched together digitally to create a single, high-resolution image of the target. Complex field measurements provide atmospheric distortion data and can be used to correct a projected beam so that it strikes the target with a nearly diffraction-limited spot size.
A number of critical challenges remain. Each component beam must be in phase with all others in order to produce a weapons effect on the target. This phasing must be maintained as both weapon platform and target move and vibrate, potentially at very high relative speeds. To complicate matters, imaging and high-power laser projection must be accomplished through the same subaperture at the same (or very nearly the same) wavelength.
Through this STTR, the Air Force Research Laboratory seeks to develop an acquisition, pointing and tracking system for optical phased array weapons. Solutions should consider atmospheric and target dynamics, sensor bandwidth limitations, 19 and 43 sub-apertures, latencies associated with digital calculations and time of fight requirements, signal-to-noise realities, target radiometry, and various system implementations.
During Phase I, the contractor will work with the military and academia to produce a detailed beam control system solution. That design should be sufficient to allow for modeling and system level parametric studies. Knowledge of high energy laser beam projection, atmospherics, platform beam
control disturbances, and optics is required. Acquisition, pointing, and target tracking are important beam control architectural details to be included in the model.
In Phase II, the contractor will implement the model developed in Phase I, perform parametric studies to refine control architecture, recommend experiments to validate the model or to acquire information needed fill in model details and reduce model uncertainty. This device will be capable of high-resolution imaging and low-power laser projection through three or more apertures while maintaining coherent beam combination in the laboratory. The product should demonstrate scalability to 19 and 43 subapertures in a real-world tactical employment.
| PHASE I: During Phase I, the contractor will work with the military and academia to produce a detailed system design. That design should be of sufficient quality to allow for the production of a low-power prototype in Phase II of this STTR.
| PHASE II: In Phase II, the contractor will produce and refine a prototype device. This device will be capable of high-resolution imaging and low-power laser projection through three or more apertures while maintaining coherent beam combination in the laboratory. The product should demonstrate scalability to 19 and 43 subapertures in a real-world tactical employment.
| PHASE III | DUAL USE COMMERCIALIZATION:
Military Application: Optical phased arrays make possible high power laser weapons on tactical and high speed aircraft as well as small, unmanned aircraft.
Commercial Application: Civilian applications for such technology include commercial aircraft self-defense and various possible welding applications. Derivative technology may make possible innovative atmospheric studies.
| References: | 1. J. W. Goodman, D. W. Jackson, M. Lehmann and J. Knotts, “Experiments in Long-Distance Holographic Imagery,” Appl. Opt. 8, 1581-1586 (1969). 2. J. W. Goodman and R.W. Lawrence, “Digital image formation from electronically detected holograms,” Appl. Phys. Lett. 11, 77-79 (1967). 3. R. A. Muller and A. Buffington, “Real-time correction of atmospherically degraded telescope images through image sharpening,” J. Opt. Soc. Am., 64, 1200–1210 (1974). 4. R.G. Paxman and J.C. Marron, "Aberration Correction of Speckled Imagery With an Image Sharpness Criterion," In Proc. of the SPIE Conference on Statistical Optics, 976, San Diego, CA, August (1988). |
| Keywords: | “Phased Arrays”, Optical, “Beam Control” |
Additional Information, Corrections, References, etc.. |
Ref #5: NEW Ref. 5: "Atmospheric Turbulence Correction Using Digital Holographic Detection: Experimental Results" by Joseph Marron at LMCT (Optics Express, Vol. 17, Issue 14, pp. 11638-11651 (2009)). (Uploaded in SITIS 8/26/10.) |
Questions and Answers: |
Q: It is difficult to understand the Air Force's current thinking regarding this technical area since the most recent reference is 22 years old. Are there more recent references of significance to which you might be able to point us? |
A: |
As of midnight September 1, questions for solicitations SBIR 10.3 and STTR 10.B will no longer be accepted.
To read the solicitation for full proposal preparation and submission details click here. |