Abstract: The automatic door opening and closing device includes: a housing having a mounting space formed therein; and a pushing and rotating assembly provided in the mounting space and having a push rod controlled to be telescopic and a guide rod which extends outwards from the mounting space and is controlled to be movable; wherein the push rod is configured to push open a door of the refrigerator when controlled to extend, and the guide rod is configured to drive the door of the refrigerator to rotate after the push rod pushes open the door of the refrigerator. By integrating the push rod and the guide rod in the mounting space inside the housing.

Abstract: A lighting apparatus and method is disclosed for illuminating a surface using solid-state light emitting diodes (LEDs). The lighting apparatus consists of a plurality of LEDs arranged in an array form, a base for mounting the LEDs, an electrical power supply, and a fixing means for attaching said lighting apparatus to a surface to provide an upward lighting. In some embodiments disclosed in the invention, the base has a shaped surface. In other embodiments, a lensing means is provided. In some embodiments, the LEDs are mounted at an angle. According to the present invention, a method for providing an upward lighting to a surface using LEDs is provided, wherein the lighting apparatus is attached near the bottom of the surface to be illuminated and the angle between the plane of said surface and the center of the light beam from the LEDs is less than 45 degrees.

Abstract: A micro-optical delay element for a time-division multiplexing scheme is disclosed wherein two light beams are provided to a beam splitter/combiner (BS/C) in the absence of optical fibre. At least one beam exiting a modulator is collimated and reaches the (BS/C) unguided as a substantially collimated beam.

Abstract: This invention relates to elements such as birefringent crystals, which are used to separate a non-collimated input beam into two orthogonally polarized sub-beams or to combine two orthogonally polarized beams into a single beam. The optical device lessens or obviates the optical path length difference encountered in prior art devices and provides a polarization beam splitter/combiner that has substantially same optical path lengths for two split or combined beams propagating therethrough. Alternatively, the device is designed to provide a selected path length difference to compensate for polarization mode dispersion in other optical devices.

Abstract: The present invention relates to bi-directional circulators based on interleaver technology, e.g. birefringent crystal interleaver technology, that enables signals containing even number ITU channels to travel in one direction through the device, while signals containing odd number ITU channels travel in the opposite direction. Open and closed three and four port devices are disclosed, as well as several useful implementations of the three port device in combination with other optical components, which result in hybrid uni-directional and bi-directional devices.

Abstract: A micro-optical delay element for a time-division multiplexing scheme is disclosed wherein two light beams are provided to a beam splitter/combiner (BS/C) in the absence of optical fibre. At least one beam exiting a modulator is collimated and reaches the (BS/C) unguided as a substantially collimated beam.

Abstract: A micro-optical delay element for a polarization time-division multiplexing scheme is disclosed wherein two light beams are provided to a polarization beam splitter/combiner (PBS/C) in the absence of optical fiber. At least one beam exiting a modulator is collimated and reaches the (PBS/C) unguided as a substantially collimated beam. In this manner the polarization state of the beam is substantially unchanged. This obviates a requirement for polarization controllers.

Abstract: Bi-directional wavelength interleaving optical isolators provide the ability to pass a first set of optical signals (e.g., ITU even channels) from a first port to a second port, while preventing a second set of optical signals from passing thereto. The bi-directional wavelength interleaving optical isolators also pass the second set of optical signals (e.g., ITU odd channels) from the second port to the first port, while preventing the first set of optical signals from passing thereto. Thus, the bi-directional wavelength interleaving optical isolator can provide bi-directional communications by passing a first set of signals in a first direction and a second set of signals in a second direction.

Abstract: The present invention relates to an optical coupling between an end of an optical fibre and an end of a lens, which provides a reliable joint with a determined spacing and angular orientation. The optical coupling permits movement of the end of the optical fibre relative to the lens in at least two alignment directions. Advantageously, the present invention permits movement of the end of the optical fibre relative to the end of the lens in a direction perpendicular to the optical axis of the lens, before the optical coupling is secured. The optical fibre within an optical fibre tube/ferrule and the lens are secured within separate sleeves and the sleeves bonded together. The end of the optical fibre and the end of the lens are optically aligned before being secured in place relative to each other. Alternatively, the invention provides similar advantages in coupling two lenses to one another via separate sleeves they are contained within.

Abstract: This invention relates to invention relates to a variable slope optical filter in the form of a Fabry-Perôt etalon having an end face with a variable finesse. A method for filtering and a variable slope optical filter for in-line use with an optical amplifier signal is also disclosed. The filter has a wavelength response that is substantially linear in slope within a band of operation wavelengths of the amplifier; the slope of the filter in an operating band of wavelengths is between zero and a only one of a positive or negative number; furthermore the filter has an amplitude response that has an opposite and counter slope as a function of wavelength to that of a gain tilt of the amplifier within the operation band of wavelengths. Relative movement between the filter and the optical amplifier signal is provided to vary the slope of the filter by means of varying the amplitude wavelength response of the filter.

Abstract: This invention relates to invention relates to a method for filtering and a variable slope optical filter for in-line use with an optical amplifier signal. The filter has a wavelength response that is substantially linear in slope within a band of operation wavelengths of the amplifier; the slope of the filter in an operating band of wavelengths is between zero and a only one of a positive or negative number; furthermore the filter has an amplitude response that has an opposite and counter slope as a function of wavelength to that of a gain tilt of the amplifier within the operation band of wavelengths. Relative movement between the filter and the optical amplifier signal is provided to vary the slope of the filter by means of varying the amplitude wavelength response of the filter.

Abstract: Tuning to maximize the isolation provided by an optical isolator to one of a predetermined plurality of wavelengths is achieved by tilting the isolator with respect to an input beam of light. Further tuning to a peak response for a given wavelength is achieved by rotation of the isolator about its longitudinal axis while or after tilting. In the manufacture of the isolator a test beam is launched into an output port end directed toward the input end. Tilting, or tiling and rotating is initiated and light at the input end is measured while tilting/rotating. When the position is determined where the minimal amount of light is measured, the optical elements are glued or secured in place, thereby providing a way to alter the response of an isolator for a given wavelength of input light.

Abstract: An optical system for coupling light from a monolithic waveguide chip from one optical path to another on different layers of the chip or into or out of the chip along an edge thereof by coupling a GRIN lens to the edge. Coupling a GRIN lens having a reflective end allows light to be launched out of and back into the waveguide chip. Alternatively a GRIN lens having a plurality of fibers coupled thereto can be used to couple signals carried by the fibers into the waveguide chip.

Abstract: An optical filter is disclosed having a pair of GRIN lenses disposed back to back, and having parallel end faces orthogonal to coaxial optical axes. Optical fiber tubes having optical fibers therein are disposed adjacent the GRIN lenses and have their inwardly facing end faces slant polished to lessen the effects of unwanted back reflections. This arrangement wherein optical axes of the optical fiber tubes are not parallel to the optical axes of the GRIN lenses is novel and inventive.

Abstract: The present invention relates to bi-directional circulators based on interleaver technology, e.g. birefringent crystal interleaver technology, that enables signals containing even number ITU channels to travel in one direction through the device, while signals containing odd number ITU channels travel in the opposite direction. Open and closed three and four port devices are disclosed, as well as several useful implementations of the three port device in combination with other optical components, which result in hybrid uni-directional and bi-directional devices.

Abstract: Bi-directional wavelength interleaving optical isolators provide the ability to pass a first set of optical signals (e.g., ITU even channels) from a first port to a second port, while preventing a second set of optical signals from passing thereto. The bi-directional wavelength interleaving optical isolators also pass the second set of optical signals (e.g., ITU odd channels) from the second port to the first port, while preventing the first set of optical signals from passing thereto. Thus, the bi-directional wavelength interleaving optical isolator can provide bi-directional communications by passing a first set of signals in a first direction and a second set of signals in a second direction.

Abstract: This invention relates to elements such as birefringent crystals, which are used to separate a non-collimated input beam into two orthogonally polarized sub-beams or to combine two orthogonally polarized beams into a single beam. The optical device lessens or obviates the optical path length difference encountered in prior art devices and provides a polarization beam splitter/combiner that has substantially same optical path lengths for two split or combined beams propagating therethrough. Alternatively, the device is designed to provide a selected path length difference to compensate for polarization mode dispersion in other optical devices.

Abstract: An optical coupling arrangement for use in an optical filter is disclosed wherein optical fibre are disposed only along one line in one orientation across an end face of an optical fibre tube having a slanted end face. By disposing slanted/polished optical fibre end faces along a line that is orthogonal to a longitudinal axis of the optical fibre tube, optimum coupling of light is achieved.

Abstract: This invention relates to a method for filtering and to a variable slope optical filter for in-line use with an optical amplifier signal. The filter has a wavelength response that is substantially linear in slope within a band of operation wavelengths of the amplifier; the slope of the filter in an operating band of wavelengths is between zero and only one of a positive or negative number; furthermore the filter has an amplitude response that has an opposite and counter slope as a function of wavelength to that of a gain tilt of the amplifier within the operation band of wavelengths. The filter having means of operating on polarized light such that different wavelengths within a band of wavelengths within the operation band are subject to different levels of attenuation according to their polarization state. A wave plate having a predetermined thickness provides a relative polarization difference between two wavelengths of an incoming beam in a controlled manner.

Abstract: This invention discloses and optical filtering arrangement wherein a filter element having a coated substrate is disposed such that its ports on one side face the substrate instead of facing the coating upon the substrate. Hence, when the filter is positioned a distance from the ports, its coating side faces away from the ports while its substrate faces the ports. In this arrangement stress applied by adhesives or solder upon the coating can be eliminated.