Abstract: A through silicon optical modulator alters a phase of a light beam which enters the back of a silicon die. The modulator can be formed as a PMOS transistor fabricated in an n-well, or can be an NMOS transistor having a negative gate to substrate voltage. By modulating the well voltage (or gate potential) the phase of a portion of the reflected light is altered. Two accumulation layers are selectively formed in the light path which is reflected from the transistor gate electrode. The phase change is detected to provide a signal from the integrated circuit having the through silicon optical modulator structure.

Abstract: An optical processor comprising, a semiconductor saturable absorber; a current source for injecting a current to the semiconductor saturable absorber; a signal light introducer for introducing a signal light to the saturable absorber; a control light introducer for introducing a control light having a wavelength not longer than the wavelength of the signal light into the semiconductor saturable absorber; an assist light introducer for introducing an assist light having a wavelength longer than the wavelength of the signal light into the semiconductor saturable absorber; and a signal light extractor for extracting the signal light after treatment by the semiconductor saturable absorber.

Abstract: An optical transmitter has a Mach-Zehnder modulator, and a feedback loop that controls the bias voltage supplied to the modulator according to the insertion loss of the modulator, to compensate for DC drift in the attenuation characteristic of the modulator. The feedback loop can be switched to provide negative feedback on either the positive or negative slope of the attenuation characteristic. Switching the slope switches the polarity of the chirp generated by the modulator, enabling positive or negative chirp to be selected, whichever produces the least dispersion penalty. Since switching the slope also switches the polarity of the modulated signal, an optical transmission system using this optical transmitter has an additional circuit that selectively inverts the transmitted or received signal.

Abstract: An electronically agile spectro-polarimetric imager is described in which an acousto-optic tunable spectral filter (AOTF) is located in series with an electronically tunable optical phase modulation plate such that incident radiation will pass through the modulation plate and the AOTF in sequence. This system makes it possible to perform both spectral analysis, complex polarization analysis and object discrimination at video-rates of incident radiation from complex target scenes according to the spectral content and polarization state of the radiation reflected or emitted from the objects within the scene, regardless of the polarization state of the incident radiation. Embodiments for analyzing incident radiation of various wavelengths are provided.

Abstract: An imaging system and method directs white light to a reflecting polarizing surface at an angle of incidence substantially equal to the Brewster angle to help maximize or greatly increase the reflected S polarized light and minimize or greatly decrease the reflected P polarized light. A contrast enhancing device also helps to reduce the reflected P polarized light. Color splitter and combining optics devices separate the reflected polarized light into a plurality of different color light components. Light modulating devices modulate each one of the color light components and rotate selectively the S polarized light and direct P polarized light toward a viewing surface. Thus, the output transmitted contrast ratio of the transmittal P polarized light to the transmitted S polarized light is enhanced.

Abstract: A solid state acoustic travelling wave lens comprises a thin core layer of acoustic and light transmissive material, such as crystalline quartz, compression-bonded between a pair of outer or cladding layers, such as fused silica, having an acoustic velocity that is only slightly higher than (e.g., less than five percent of) that of the core material. The acoustic mode field characteristic of the weakly guiding device contains no spatial variations caused by Fresnel diffraction in an unguided wave device. In a second embodiment, shear stress coupling between the core and cladding layers is inhibited by interposing very thin liquid boundary layers between the core layer and the cladding layers. Such thin liquid boundary layers, which are relatively more compressible than the core and cladding material, allow longitudinal waves to be transmitted across the core/cladding boundary (through the liquid), but prevent transmission of shear waves therebetween.

Abstract: A laser beam intensity modulation system has a variable delay circuit that is used to control the relative delay in the delivery of a video signal between two cascaded AOM's. This delay circuit is controlled by a delay controller that monitors the intensity modulation of the laser beam to provide feedback control. This system maximizes the rise and fall times of the beam to generate precise beam modulation required for high speed image setters.

Abstract: A spatial light modulator and a lighting system used in, for example, projection displays are provided. The lighting system has a polarizing plate optically disposed in parallel to a light modulating layer of the spatial light modulator, thereby orienting the polarization of readout light beams incident on the spatial light modulator in the same direction to increase the contrast of images projected on a screen. The spatial light modulator is provided with a coupling prism having a side surface opposed to an entrance surface on which the readout light beams are incident. The side surface is so inclined inward as to allow stray light in the coupling prism to go out of the coupling prism without being reflected, thereby eliminating a decrease in contrast of images with a screen caused by the stray light.

Abstract: An acoustic traveling wave lens structure for an acousto-optic scanner comprises a confined height fluid-containing channel, upon which a scanned optical beam to be modulated by a acoustic traveling wave is incident. The channel is bounded by spaced-apart walls that extend between a first end of the scanner channel, to which an acoustic transducer is coupled, and a second end of the channel that terminates an acoustic traveling wave launched from the acoustic transducer. The thickness of the channel is linearly tapered from the first end to the second end, so as to maintain a constant acoustic power density. To compensate for the attenuation in acoustic power through the water medium, the waveguide may be heated, to maintain the temperature of the liquid medium (water) within the waveguide channel within a prescribed temperature range over which the acoustic velocity remains substantially constant or undergoes a relatively small variation.

Abstract: A passive infrared motion detector that creates a detection pattern with non-diverging insensitive zones. The sensing elements are of alternating polarity and each has a width w. An optical collection system directs infrared radiation onto the sensing elements. The sensing elements are separated by a distance equal to an integer multiple of width w, with the integer being at least two. The optical centers of the optical collection system are separated by an integer multiple of width w, with the integer being at least two. The arrangement of the optical centers and the sensing elements results in a detection pattern with non-diverging insensitive zones, with the insensitive zones having a negligible width.

Abstract: In a measurement method for measuring the epitaxial film thickness of a multilayer epitaxial wafer, a reflectivity spectrum of a multilayer epitaxial wafer having at least two epitaxial layers of different electric characteristics is measured by using infrared radiation in a far infrared region of at least 500 cm.sup.-1 or less, and frequency-analysis is performed on the reflection spectrum thus obtained by a maximum entropy method, and the film thickness of each epitaxial layer is calculated on the basis of the analysis spectrum thus obtained.