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Optical Engineering

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spatial light modulators; optical phased arrays; nonmechanical beam steering; broadband beam steering




An array of phase retarders can be used as an optical phased array (OPA) to steer light [McManamon et al., Proc. IEEE 84 (2), 268 298 (1996)]. The introduction of resets enables steering to larger angles without requiring an optical path difference (OPD) greater than one wavelength. These resets, however, are correct only at the design wavelength. The beam steerer is therefore very dispersive. It has been shown theoretically that resets of an integer multiple of the wavelength will make the beam steerer less dispersive [McManamon and Watson, Proc. SPIE 4369, 140-148 (2001)]. We offer the first experimental proof that resets of n lambda are less dispersive than resets of a single lambda. We also show experimentally that the dispersion associated with fixed period resets does vary, but only within a fixed limit. Last, we show the equivalent of power shifting from one order to the next as larger resets move from being divisible by one integer times the nondesign wavelength toward being divisible by the next integer times the nondesign wavelength. (c) 2005 Society of Photo-Optical Instrumentation Engineers.


Copyright 2005 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

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