Aberration limits for annular Gaussian beams for optical storage.

Annularly apodized beams have been suggested for use in optical storage because of their potential to go beyond the conventional spot size and depth-of-focus limits. One concern for such applications is the effects of small aberrations on beams in which the energy is concentrated in a small annular ring. We present calculations and experimental results that show that annular apodization of a Gaussian beam reduces the sensitivity to defocus as well as balanced spherical and coma aberrations.

Holographic light deflection.

An operational holographic laser light deflector is described, which is well suited for applications requiring fast constant-speed scanning, high resolution, and moderately large angles of deflection. A particularly unique application of this device as an opaque document scanner is also described.

Spatial pulse modulation.

Pulse modulation of electronic time signals is a well-proven concept, particularly in the context of data communications and computers. We suggest that pulse modulation of spatial optical signals might be another fruitful concept. The optical components and optical methods for performing the necessary operations for spatial pulse modulation are available.