Martin Marietta Corporation

Lockheed Martin Corporation

Kenneth J Ritter

Terrance L Worchesky

Maher E Tadros

Wenpeng Chen

Shekhar Guha

Keith Kang

Robert James Martin

Barry L Lane

An optical memory material includes a two-photon storage component which can be written from a first to a second state in response to WRITE light, mixed with a signal component which fluoresces by one-photon absorption only at the written locations in response to READ light. The storage material may be a fulgide. The memory material may also include a frequency upconversion material to aid writing. Writing is performed by a spatial light modulator (SLM) with a dynamic focussing system, for concentrating sufficient power at WRITE locations for nonlinear two-photon absorption. Crosstalk is avoided during simultaneous writing in some embodiments, by spacing the individual WRITE beams apart by an integer number of inter-beam spacings, so that non-adjacent datels are written simultaneously in a 'paragraph,' and the non-written areas are written at a different time with different paragraphs. The memory material may be translated relative to the SLM to access different paragraphs, or accessed by an electronically sparsed SLM. Reading uses a sheet of READ light traversing the pages of written material to cause the signal component to fluoresce, and imaging the fluorescent pattern onto a detector array. The memory material may be stacked in layers, spaced apart by light waveguides, for guiding the READ beam to the page to be read. In another embodiment, writing and erasure are performed by a modulated quasi-one-dimensional sheet of light, intersecting a second, unmodulated sheet of light at a column within the memory material.

Optical volume memory

A SAR radar has an optical processor which uses an electrical-signal-to-light modulator. The modulator includes a tapped delay line which may be either analog or digital, and the signals tapped from the delay line are applied to an array of temporary storage elements, which in the case of analog signals may be a capacitive sample-and-hold, or for digital signals may include storage registers. In order to improve the signal-to-noise ratio (SNR) by comparison with a processor using an acoustic modulator, the signals tapped from the delay line are sampled at a display sampling rate, which is very low by comparison with the signal sampling rate or the highest frequency of interest, and the sampled signals are held until the next following display rate pulse. The signals held in the temporary storage elements are applied to the modulator elements, so that the optical pattern remains fixed for relatively long periods of time during which the optical processing can integrate photons for improved SNR.

Mutiple-clock controlled spatial light modulator

A device for converting a set of electronic signals that represent an image into a coherent image includes a two-dimensional array of asymmetric Fabry-Perot (ASFP), quantum-well-based optical modulators connected on a pixel-by-pixel basis to a two-dimensional array of drive circuits located on an integrated circuit. Electronic signals received by the integrated circuit cause the pixel drive circuits to change a bias voltage applied across the optical modulator section and, thereby, change the optical properties of the optical modulator section of the device. The two-dimensional array can be used to impart intensity-only, phase-only, or phase-and-intensity variations onto a beam of coherent laser light incident on the array. This coherent image can be used with other optical elements to form optical processing machines and optical storage devices.

Hybridized asymmetric fabry-perot quantum well light modulator

Growing community of inventors

Sykesville, MD, United States of America

Kenneth J Ritter