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AssigneeUniversity of Rochester
InventorsThomas W. Stone, Nicholas George
Estimating the term…
Achromatic optical systems forming phase shifters and phase modulators are presented and shown to impart (temporal) phase-angle shifts in incoming waves which are independent of wavelength over extremely broad spectral ranges (achromatic or white light). Three major classes of achromatic phase shifters are described including the triangle, close cascade, and imaged grating configurations. When constructed utilizing volume holographic optical elements, very high diffraction efficiencies may be achieved over the large bandwidths used. These systems may similarly be utilized to impart achromatic frequency shifts and frequency modulations which are wavelength independent over extreme spectral ranges and usually do not disturb the spatial form of the input waves. These devices may be used in AC interferometers and allow such interferometers to be operated with white light. The devices are also useful in switching between spatial sine and cosine optical transforms in optical pattern recognition systems.
An optical system for processing light having a broad spectrum of wavelengths in which the optical phase of the light is changed achromatically which comprises a diffraction element on which a beam of input waves of said light is incident and from which diffracted light exits, displacement providing means for displacing said diffraction element transversely to said beam of input waves, and means for providing an output beam of said diffracted light in which the spatial form of the input waves is not substantially disturbed in response to a displacement of said element in a direction transverse to said beam of input waves to change the phase of said diffracted light achromatically.
Dependencies are inferred from the claim text.