Martin Marietta Corporation

Lockheed Martin Corporation

Wenpeng Chen

Shekhar Guha

Terrance L Worchesky

Maher E Tadros

Kenneth J Ritter

Keith Kang

Claude C Frazier, Iii

Norman E Byer

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

An optical power limiter and switch, transparent at low light intensity and opaque at high intensity, is comprised of a pair of right triangular prisms separated by a liquid film whose refractive index changes in response to optical energy. A first or input lens focuses the light upon the liquid film at an angle less than the critical angle of total reflection of the prism-liquid interface and a second or output lens refocuses the energy to a detector through an aperture. When the intensity of the optical energy reaches a first predetermined level, the optical energy is defocused and diverted from the detector. When the intensity of the optical energy reaches a second predetermined higher level, the critical angle is achieved whereupon the optical energy is reflected away from the interface rather than through it. The liquid material of the film also includes an optically absorbent dye for attenuating optical energy of predetermined wavelengths transmitted through the film prior to defocusing and total reflection.

Optical switch device

The present invention relates to a device for optical switching, frequency conversion, and protection of sensory organs and optical and electronic sensors which comprises at least one layer comprising a polymerized transition metal poly-yne.

Poly-yne nonlinear optical materials

A semiconductor device is optically phase-locked by utilizing (1) the Burstein shift in differently doped semiconductor layers and injecting light having an energy level lower than the absorption edge of the heavily doped layer in which optical absorption is not desired and higher than the more lightly doped region where it is desired; and (2) the internal photoemission and injecting light having an energy level lower than the band gap of the semiconductor.

Growing community of inventors

Bethesda, MD, United States of America

Wenpeng Chen