Abstract:
A system and method for performing field measurement and testing of a plurality of widely spaced laser beams used in visual warning technology (VWT). VWT uses a combination of widely spaced laser beams, to warn civilians from approaching too close to military security areas. The widely spaced laser beams are displaced using rhomboidal prisms. Each rhomboidal prism receives a corresponding laser beam and displaces it toward a collecting lens. The lens focuses the displaced beams received thereon onto an imaging sensor for testing. Beam shutters may be used for selectively blocking one or more beams in order to test the beams separately and in different combinations.
Abstract:
A novel electro-optical sensor for the wideband and normalized translation of the two-dimensional position of a light beam transverse to its traveling direction into electrical position signals. Incident on the sensor is the light beam 122 which is divided with a beamsplitter 121 into a transmitted beam 123 and a reflected beam 124 which both have similar transverse motion behavior as the incident beam. From each of these divided beams the position is determined one-dimensionally with an one-dimensional optical position sensor, 125, 126. The one-dimensional position determination is done by dissecting each divided beam into two beams using a partitioning element. The outputted dissected beams have a power distribution that depends on the position of the divided beam relative to the partitioning element. Each beam is optically coupled to a photo detector which translates its power into an electric current. In each circuit 127, 128, the two photo detectors are reverse biased and electrically connected in series. The node connecting them is a current type position output. The sum current through the two photo detectors is determined using two current mirrors. The first mirrors the current through one photo detector, the second mirrors the output current of the first current mirror plus the current through the second photo detector and outputs a current type sum signal. Each position signal is normalized with respect to its sum signal using an analog-to-digital converter, 129, 130, with the sum signal coupled to the reference input and the position signal coupled to the regular signal input.
Abstract:
An optical fiber assembly includes a prism, four first collimating portions, four second collimating portions, two third collimating portion, two light emitting elements, two light receiving elements, four optical fibers, and two light intensity detectors. The prism includes an incident surface, a first reflecting surface, a first emergent surface, a second reflecting surface, and a second emergent surface.The first collimating portions are positioned on the incident surface. The second collimating portions are positioned on the first emergent surface. The third collimating portions are positioned on the second emergent surface. Each light emitting element faces one of the first collimating portions for emitting light beams. Each light receiving element faces one of the first collimating portions. Each optical fiber faces one of the second collimating portions. Each light intensity detector faces one of the third collimating portions for detecting light intensity of a corresponding light emitting element.
Abstract:
Systems and methods for increasing the quantum efficiency of a photocathode used in an intensified an intensified array detector with a photocathode, such as a charge-coupled device (ICCD) are presented. A quantum efficiency enhancement device is disposed in front of an ICCD and is configured to enable or facilitate an increase in the angle of incidence of incoming rays incident on the photocathode. The ICCD itself may be tilted to achieve an increased angle of incidence, and such tilting is preferably only in a direction in which pixel columns of the ICCD extend such that a plane of incidence of incoming light to the ICCD is perpendicular to a direction of wavelength dispersion. The quantum efficiency enhancement device may include re-imaging optics, an optical tilt compensator and optical coupler.
Abstract:
An optical sensing system including a sensing plate, a light guiding device, and a detecting device is provided. The sensing plate has a light-pervious area. The light guiding device is disposed behind the sensing plate and used for reflecting an incident light proceeding along an incident direction, so as to form a first reflective light proceeding along a first direction and toward the light-pervious area. The incident direction is approximately perpendicular to the first direction. The detecting device is disposed behind the light guiding device. When an external surface of the light-pervious area is shaded by an object, the first reflective light is reflected by the object and forms a second reflective light proceeding toward the detecting device. Once receiving the second reflective light, the detecting device generates a sensing signal.
Abstract:
Systems and methods for increasing the quantum efficiency of a photocathode used in an intensified an intensified array detector with a photocathode, such as a charge-coupled device (ICCD) are presented. A quantum efficiency enhancement device is disposed in front of an ICCD and is configured to enable or facilitate an increase in the angle of incidence of incoming rays incident on the photocathode. The ICCD itself may be tilted to achieve an increased angle of incidence, and such tilting is preferably only in a direction in which pixel columns of the ICCD extend such that a plane of incidence of incoming light to the ICCD is perpendicular to a direction of wavelength dispersion. The quantum efficiency enhancement device may include re-imaging optics, an optical tilt compensator and optical coupler.
Abstract:
Polarimeters based on transversal division of the input beam and use of different polarization elements in different polarization states to change polarizations of different portions of the input beam so that the power levels of the different portions of the input beam can be measured to determine the polarization state of the input beam. A wedged substrate can be used to direct the different portions of the input beam at different directions and a lens can be used to focus these different portions at different locations at a plane.
Abstract:
A polarization separating element such as a beam splitter receives a first light of a first polarization plane. The polarization separating element derives out of the first light a second light of a second polarization plane set perpendicular to the first polarization plane. A photoelectric element converts the second light into an electric signal. The intensity of the second light is in this manner detected. Since the second light is derived out of the first light, the phase of the second light is allowed to synchronize with the phase of the first light. The extinction ratio of the second light accurately reflects the extinction ratio of the first light. The detection of the intensity of the second light at the photoelectric element enables an accurate detection of the intensity of the first light.
Abstract:
There is provided a scanning system, including a main housing, and at least one optical wedge (12) rotatable about a shaft means (40) located within the main housing, wherein a laser beam having an optical axis and incident on the optical wedge (12), is refracted at least once by the wedge; characterized in that the shaft means (40) passes through the center of the at least one wedge (12) and that the optical axis of the incident laser beam is substantially parallel to, but laterally offset from, the shaft means (40).
Abstract:
A unicell photometer of the photoelectric type having a single tilted plano-convex lens with a series of spaced prisms integrated with the plano surface to provide the photometer with different horizontal and vertical specific acceptance angles while simultaneously aiming the field of view of the photometer below the horizontal plane.