Abstract:
An optical multiplexer/demultiplexer for fiber optical communication is disclosed. The device includes a collimator (21), configured to collimate a beam of wavelength-division-multiplexed signal received from a fiber (20); a splitter (23) for dividing the beam into two parallel beams which are polarized 90 DEG from each other; a retarder, such as a half-wave plate, for rotating the polarization direction of one of the beam by 90 DEG so that both beams are polarized in the same direction; a beam steerer, such as a prism (25), for modifying the diameter in the direction parallel to the polarization direction and for modifying the propagation direction; a wavelength dispersing element, such as a diffraction grating (27), for separating each of beams into a plurality of beams, each having a different center wavelength and propagating along a different angular direction. The optical elements in the multiplexer/demultiplexer are arranged in such a way to direct the diffracted beams through the optical elements, in reverse order, resulting in a plurality of beams, which may be launched into optical fibers (33). The parameters of the optical elements may be chosen to be suitable for multimode dense WDM applications using single-mode transmission fiber.
Abstract:
A method and apparatus for automatically providing for both multiplexing and independent external modulation of two or more wavelengths emitted by a multi-longitudinal mode laser. The present invention uses an integrated optics device chip to enable coupling of the dispersed wavelengths into separate electro-optic modulators which encode each of the carrier wavelengths with a different signal. Accordingly, the volume of data which can be transmitted over an optical fiber network is increased.
Abstract:
The invention is an AlxGa1-xN ultraviolet detector with extremely high responsivity at over 200 to 365 nanometers and a very sharp long wavelength cutoff. The active layer for the sensors is a single crystal AlxGa1-xN preferably deposited over a basal plane sapphire substrate using a switched atomic layer epitaxy process.
Abstract:
An optical multiplexer and demultiplexer for dense wavelength division multiplexed ("DWDM") fiber optic communication systems is disclosed. As a multiplexer, the device functions to spatially combine the optical signals from several laser sources (each of which is a different wavelength) and launch the spatially combined laser beams into a single optical fiber. As a demultiplexer, the device functions to spatially separate the different wavelengths of WDM optical link and launch each of the different wavelengths into a different optical fiber. The device includes both bulk optic and integrated optic components. The spatial separation or spatial combination of laser beams of different wavelength is achieved with the use of bulk diffraction gratings. Also, bulk optical components are used to collimate and shape (or steer) the free space propagating laser beams to enable efficient coupling of light into single mode optical fibers, or integrated optic waveguides, and to reduce optical crosstalk.
Abstract:
An optical multiplexer/demultiplexer for fiber optical communication is disclosed. The device includes a collimator (21), configured to collimate a beam of wavelength-division-multiplexed signal received from a fiber (20); a splitter (23) for dividing the beam into two parallel beams which are polarized 90° from each other; a retarder, such as a half-wave plate, for rotating the polarization direction of one of the beam by 90° so that both beams are polarized in the same direction; a beam steerer, such as a prism (25), for modifying the diameter in the direction parallel to the polarization direction and for modifying the propagation direction; a wavelength dispersing element, such as a diffraction grating (27), for separating each of beams into a plurality of beams, each having a different center wavelength and propagating along a different angular direction. The optical elements in the multiplexer/demultiplexer are arranged in such a way to direct the diffracted beams through the optical elements, in reverse order, resulting in a plurality of beams, which may be launched into optical fibers (33). The parameters of the optical elements may be chosen to be suitable for multimode dense WDM applications using single-mode transmission fiber.
Abstract:
A method and apparatus for automatically providing for both multiplexing and independent external modulation of two or more wavelengths emitted by one or more multi-longitudinal mode laser(s) (26) or other light source. The present invention uses an integrated optics device chip to enable coupling of the dispersed (27) wavelengths into separate electro-optic modulators (131) which encode each of the carrier wavelengths with a different signal. Accordingly, the volume of data which can be transmitted over an optical fiber network is increased. The carrier wavelengths can be transmitted over single or multi-mode optical fibers.
Abstract:
A method and apparatus for splitting, scanning and receiving a beam of light is disclosed. Binary optic array components are used to split, in an angular manner, an input beam into multiple beams, travelling in different directions. Miniaturized array element BOCs arranged in ''n'' different groups are used, wherein n is dependent upon the number of split beams needed or desired. An offset is introduced between the optical axis of each of the corresponding pair of miniaturized BOCs. By varying the offset over time, the resultant beam(s) can be scanned in one, two or three dimensions. Piezo-electric drivers controlled by a processor may be used to move the array in order to vary the offset. The device may also include a collection area to collect the returned scanned beams by using an array of optic components integrated with the scanner. The collected beams are then focused onto detectors.