Abstract: In one aspect, a method includes forming a pit in a top surface of a substrate by removing a portion of the substrate and growing a semiconductor material with a bottom surface on the pit, the semiconductor material different than the material of the substrate. The pit has a base recessed in the top surface of the substrate. In another aspect, a structure includes a substrate having a top surface, the substrate including at least one pit having a base lower than the top surface of the substrate, and a semiconductor material having a bottom surface formed on the base of the pit.

Abstract: A method and apparatus is disclosed for enabling a coupling of at least one optical fiber with an optoelectronic device. The apparatus comprises at least one v-groove for receiving at least one optical fiber. A first end of the apparatus is then polished at a predetermined angle in order to enable an optical coupling with the optoelectronic device.

Abstract: A multi-spectrum, multi-channel imaging spectrometer includes two or more input slits or other light input devices, one for each of two or more input channels. The input slits are vertically and horizontally displaced, with respect to each other. The vertical displacements cause spectra from the two channels to be vertically displaced, with respect to each other, on a single image sensor on a stationary image plane. The horizontal displacements cause incident light beams from the respective input channels to strike a convex grating at different respective incidence angles and produce separate spectra having different respective spectral ranges. A retroflective spectrometer includes a convex grating that, by diffraction, disperses wavelengths of light at different angles and orders approximately back along an incident light beam. A single concave mirror reflects both the input channel and the dispersed spectrum.

Abstract: There is provided an optical assembly and a method for assembling components of the optical assembly, the method comprising: providing a structure for guiding light; providing a plurality of optical fibers embedded in a fixed arrangement in the structure, the optical fibers for coupling the light from a coupling surface the structure; abutting a first package against the coupling surface, such that each one of multiple elements comprised in the first package is substantially aligned with each one of a first group of optical fibers in the plurality of optical fibers; and abutting a second package against the coupling surface, adjacent to the first package, and such that: the first and the second package are spaced apart by a gap; and each one of multiple elements comprised in the second package is substantially aligned with each one of a second group of optical fibers in the plurality of optical fibers, the gap providing a tolerance in a position of any one of: each one of the elements in the packages; the pac

Abstract: Illumination exposure control systems comprising reflective pixelated spatial light modulators that reflect substantially all of the light impinging on them into at least two different light paths. At least one of the light paths acts as a propagating light path and transmits the light beam out of the lighting system. At least one other light path acts as a non-propagating light path and prevents the light beam from being transmitted out the system. The illumination exposure control systems provide high speed of exposure actuation and precision control of exposure duration and frequency or exposure sequences.

Abstract: In one exemplary embodiment, a method comprises transmitting an optical signal via the optical line, measuring a relative change in spectral intensity of the optical signal near a clock frequency (or half of that frequency) while varying a polarization of the optical signal between a first state of polarization and a second state of polarization, and using the relative change in spectral intensity of the optical signal to determine and correct the DGD of the optical line. Another method comprises splitting an optical signal traveling through the optical line into a first and second portions having a first and second principal states of polarization of the optical line, converting the first and second portions into a first and second electrical signals, delaying the second electrical signal to create a delayed electrical signal that compensates for a DGD of the optical line, and combining the delayed electrical signal with the first electrical signal to produce a fixed output electrical signal.

Abstract: Methods for driving a plurality of MEMS devices in an apparatus are described. A voltage pulse is applied to an electrode or a structure portion of a MEMS device. The electrode is on the substrate underneath the structure portion. At least two MEMS devices of the plurality of MEMS devices have different threshold voltages, and the threshold voltage is the minimum voltage required to move the structure portion. A bias voltage is applied to whichever of the electrode or the structure portion of the MEMS device does not have the voltage pulse applied thereto. The bias voltage and the voltage pulse are capable of moving the structure portion of the MEMS device that has the higher threshold voltage of the different threshold voltages.

Abstract: In one exemplary embodiment, a method comprises transmitting an optical signal via the optical line, measuring a relative change in spectral intensity of the optical signal near a clock frequency (or half of that frequency) while varying a polarization of the optical signal between a first state of polarization and a second state of polarization, and using the relative change in spectral intensity of the optical signal to determine and correct the DGD of the optical line. Another method comprises splitting an optical signal traveling through the optical line into a first and second portions having a first and second principal states of polarization of the optical line, converting the first and second portions into a first and second electrical signals, delaying the second electrical signal to create a delayed electrical signal that compensates for a DGD of the optical line, and combining the delayed electrical signal with the first electrical signal to produce a fixed output electrical signal.

Abstract: In one exemplary embodiment, a method comprises transmitting an optical signal via the optical line, measuring a relative change in spectral intensity of the optical signal near a clock frequency (or half of that frequency) while varying a polarization of the optical signal between a first state of polarization and a second state of polarization, and using the relative change in spectral intensity of the optical signal to determine and correct the DGD of the optical line. Another method comprises splitting an optical signal traveling through the optical line into a first and second portions having a first and second principal states of polarization of the optical line, converting the first and second portions into a first and second electrical signals, delaying the second electrical signal to create a delayed electrical signal that compensates for a DGD of the optical line, and combining the delayed electrical signal with the first electrical signal to produce a fixed output electrical signal.

Abstract: An optical switch includes an optical waveguide to route an input optical beam. At least one polarization switch receives the input optical beam from the optical waveguide. At least one birefringent wedge is associated with the at least one polarization switch. The at least one polarization switch and at least one birefringent wedge operate to direct the input optical beam to two or more output locations through control of the polarization switch.

Abstract: An optical switching apparatus includes at least one optical waveguide to deliver at least one input optical beam. A dispersion device spatially separates the at least one input optical beam into individual wavelength channels. An optical power device aligns the individual wavelength channels. An optical switch has at least one transflective polarizing element, at least one birefringent wedge and at least two polarization switches. The individual wavelength channels are directed to independently addressable regions of the polarization switches for wavelength selective switching. A second optical power device aligns the individual wavelength channels from the optical switch. A second dispersion device spatially combines individual wavelength channels from the second optical power device. At least one output optical waveguide receives at least one of the individual wavelength channels from the second dispersion device.

Abstract: A method for manufacturing a semiconductor device includes: forming a protrusion-patterned layer on a substrate, the protrusion-patterned layer including a plurality of separated protrusions, each of which includes a base portion formed on the substrate and a top end portion opposite to the base portion; laterally growing a base layer on the top end portions of the protrusions of the protrusion-patterned layer in such a manner that each of the top end portions is covered by the base layer and that the base layer cooperates with the protrusions to define a plurality of cavities thereamong; thickening the base layer to a predetermined layer thickness; and separating the base layer from the substrate by destroying the protrusions of the protrusion-patterned layer.

Abstract: The present invention teaches a device for converting solar radiation to electrical energy comprising a thin film, single crystal device chosen from a variety of semiconductor materials, optionally, employing an alternative substrate, and various combinations of p-n, p-i-n and avalanche p-i-n diodes to enable high conversion efficiency photo-voltaic devices.

Abstract: In accordance with one embodiment of the present invention, an antenna assembly comprising an antenna portion and an electrooptic waveguide portion is provided. The antenna portion comprises at least one tapered slot antenna. The waveguide portion comprises at least one electrooptic waveguide. The electrooptic waveguide comprises a waveguide core extending substantially parallel to a slotline of the tapered slot antenna in an active region of the antenna assembly. The electrooptic waveguide at least partially comprises a velocity matching electrooptic polymer in the active region of the antenna assembly. The velocity ?e of a millimeter or sub-millimeter wave signal traveling along the tapered slot antenna in the active region is at least partially a function of the dielectric constant of the velocity matching electrooptic polymer.

Abstract: Switching optical signals containing a plurality of spectral channels characterized by a predetermined channel spacing is described. A selected beam deflector array may be selected from among a plurality of available beam deflector arrays configured to accommodate spectral channels of different channel spacings. The selected beam deflector array is configured to accommodate spectral channels of the predetermined channel spacing. The spectral channels are selectively optically coupled to the selected beam deflector array, which selectively optically couples the spectral channels between one or more input ports and one or more output ports.

Abstract: A micro mirror device is described. The device has a tiltable mirror plate with a reflective surface configured to reflect incident light to form a reflected light beam. A controller is configured to cause the mirror plate to tilt from an un-tilted position to an “off” position, a first “on” position, or a second “on” position. An opaque aperture structure is configured to block substantially all of a reflected light beam from reaching a display surface when the mirror plate is tilted to the “off” position, allow a first portion of a reflected light beam to pass through when the mirror plate is tilted to the first “on” position and allow a second portion of a reflected light beam to pass through when the mirror plate is tilted to the second “on” position. The tilting positions determine a brightness of display pixels.

Abstract: Color endoscopes, light sources and endoscopy systems, etc., that have good dynamic range and/or resolution while reducing the size and cost of the endoscopes. The endoscopes achieve this, in part, by using a black and white (grayscale or monochromatic) sensor at the tip of the endoscope instead of a color sensor. The endoscope uses a light system that precisely and specifically illuminates the tissue one color at time, captures the image in grayscale, then uses a computer to associate the image with the color. Certain aspects of the invention apply to imaging systems in addition to endoscopes.

Abstract: Methods and systems for increasing the threshold for stimulated Brillouin scattering are described. A seed source may generate one or more chirped seed pulses characterized by a pulse duration ?, and a frequency chirp. The pulse duration ? may be greater than about 2 nanoseconds. A photonic crystal amplifier amplifies the seed pulses to produce one or more amplified pulses characterized by a peak power P greater than about 1 kilowatt. The pulse duration ?, frequency chirp, and the photonic crystal fiber may be selected such that a threshold for stimulated Brillouin scattering (SBS) in the photonic crystal fiber is greater than the peak power P.

Abstract: A white-light emitting semiconductor device includes a first light-emitting die, a second light-emitting die, a photostimulable luminescent substance, and a holding assembly. The first light-emitting die emits a first radiation having a first wavelength range. The second light-emitting die emits a second radiation having a second wavelength range, and a third radiation having a third wavelength range different from the second wavelength range. The photostimulable luminescent substance is excitable to emit a fourth radiation having a fourth wavelength range. The fourth radiation is mixed with the first, second, and third radiations to result in white light. The holding assembly holds the first and second light-emitting dies, and the photostimulable luminescent substance.

Abstract: Atomic layer epitaxy (ALE) is applied to the fabrication of new forms of rare-earth oxides, rare-earth nitrides and rare-earth phosphides. Further, ternary compounds composed of binary (rare-earth oxides, rare-earth nitrides and rare-earth phosphides) mixed with silicon and or germanium to form compound semiconductors of the formula RE-(O, N, P)—(Si,Ge) are also disclosed, where RE=at least one selection from group of rare-earth metals, O=oxygen, N=nitrogen, P=phosphorus, Si=silicon and Ge=germanium. The presented ALE growth technique and material system can be applied to silicon electronics, opto-electronic, magneto-electronics and magneto-optics devices.