Abstract: A beam steering device (300) for deflecting a beam of light is provided. The beam steering device comprises a first deflecting member (310), a rotating member (320), and a second deflecting member (330). For an incoming beam of light having components (303, 302) with their polarization parallel (303?) and perpendicular (302?), respectively, to an optic axis (314, 334) of the beam steering device, the parallel component (303) is deflected by a first angle (304) when passing the first deflecting member. When passing the rotating member, the polarization (303?, 302?) of the beam of light is rotated by 90 degrees (303?, 302?). When passing the second deflecting member, the perpendicular component (302) is deflected by a second angle (305).

Abstract: A fiber-optical, wavelength selective switch, especially for channel routing with equalization and blocking applications. The input signals are converted to light beams having predefined polarizations (41). The beams are then laterally expanded (43), and then undergo spatial dispersion in the beam expansion plane. The different wavelength components are directed through a polarization rotation device, pixilated along the wavelength dispersion direction such that each pixel operates on a separate wavelength. Each beam is passed into a pixilated beam steering array (48), for directing each wavelength to a desired output port. The beam steering devices can be MEMS-based or Liquid crystal-based, or an LCOS array. When the appropriate voltage is applied to a pixel and its associated beam steering element, the polarization of the light passing through the pixel is rotated and the beam steered to couple to the selected output port.

Abstract: A polarization controller includes a phase retarder having a rotation about an {1,0,0} axis that receives an optical signal from a waveguide structure. At least one nanoelectromechanical dielectric perturber produces ±45° birefringent axes by placing the at least one nanoelectromechanical dielectric perturber at selective positions around the phase retarder to produce dynamic change in the effective index in one of the modes existent in an extraordinary axial direction.

Abstract: Some projection systems use a polarization beamsplitter (PBS) for coupling light to and from an image-forming device. The PBS is typically formed with a reflective polarizing layer disposed between glass covers. Stress birefringence in the glass cover lying between the reflective polarizing layer and the image-forming device can reduce the image contrast of the projection system. A quarter-wave retarding element positioned between the glass cover and the image-forming device is used to compensate for the birefringence, at least in part. This permits the PBS to use glass covers formed of a glass material having a higher stress optic coefficient than before, while still maintaining high image contrast.

Abstract: In a variable optical delay circuit to be used for compensation for polarization mode dispersion of an optical signal and for other purposes, there are provided a first birefringent member, a second birefringent member and a variable optical rotator interposed between the first birefringent member and the second birefringent member for varying a polarization state of light outputted from the first birefringent member. The birefringent members and the variable optical rotator are disposed on the same optical axis, and the optical axis of each of the birefringent members is set to perpendicularly intersect a traveling direction of inputted light. Therefore, by varying the optical rotation angle of the variable optical rotator, an arbitrary delay quantity corresponding thereto is obtainable in a continuous (analog-like) fashion without undergoing spatial separation between polarization components of the inputted light and varying the intensity (loss) of each of the polarization components.

Abstract: Methods and devices are provided for steering an electromagnetic beam. The device includes a reflective element, a polarizer, a relay focusing element, and a modulation element. The polarizer is configured to transmit light of a specified polarization and to reflect light having other than the specified polarization. The relay focusing element is disposed to provide optical paths for the electromagnetic beam from a first spot position to a second spot position spatially displaced from the first spot position such that the optical paths encounter the reflective element and the polarizer. The modulation element is configured for selectively transforming a polarization of the electromagnetic beam to include a component of the specified polarization at a spatially localized position along the optical paths.

Abstract: The present invention is directed to an optical space switch accommodating a plurality of input light paths and output light paths. The optical space switch comprises a plurality of polarization control optical switches, each consisting essentially of: polarization control means having elements, one for each input light path, for rotating through 90° the polarizing direction of light information incident from each input light path or otherwise retaining the polarizing direction thereof for output; and a light path routing element for routing the light path for the light information output from the polarization control means in accordance with the polarizing direction of the light information. These polarization control optical switches are arranged in a matrix pattern or coupled in cascade to implement a polarization control optical space switch.

Abstract: An optical gate according to the invention comprises a polarization divider to divide an optical signal into two orthogonal polarization components and to output them as a first polarization component which precedes in the time base and a second polarization component which follows the first one in the time base; a semiconductor optical amplifier to modulate the phase of the second polarization component output from the polarization divider according to a control light; an assist light supplier to supply to the semiconductor optical amplifier an assist light to help the recovery of the refractive index variation of the semiconductor optical amplifier caused by the control light; a polarization combiner to combine the first and second polarization components of the optical signal transmitting on the semiconductor optical amplifier so as to adjust them in the same time location; and a polarization extractor to extract a predetermined polarization direction component from the output from the polarization combine

Abstract: A polarization mode dispersion generator for generating polarization mode dispersion (“PMD”) spectra is provided. The generator includes a plurality of birefringent stages, each stage including a differential group delay (“DGD”) element and a phase-shifting element. The generator is capable of inducing an amount of polarization mode-mixing between at least one adjacent pair of stages. The shape of a PMD spectrum can be preserved while frequency shifting the spectrum in either direction. Alternatively, the shape of the PMD spectrum can be changed without frequency shifting.

Abstract: An optical isolator comprises two polarizers arranged before and after an optical rotator and a magnet surrounds the optical rotator. The magnet may generate a magnet field with a direction in spatial space parallel to the propagation direction of light traveling in the optical rotator and a strength sufficient to rotate the light to a predetermined rotation angle. Preferably, the polarizers are birefringent wedges of identical shape and optical properties. The magnet in accordance with the present invention may have a pair of magnetic adapters to generate the desired direction and strength of magnetic field. The direction of magnetic field varies in three-dimension space as the magnet is adjusted. The present invention provides an optical isolator of high isolation for high-volume mass production at a low cost. In particular, it may be easily operated at different wavelengths to achieve desired isolation without sacrifice of other optical properties of the optical isolator.

Abstract: An optical beam splitter separates an input beam into two exit beams which angularly diverge from each other by a continuously variable amount. The degree of angular divergence is controlled by rotating a compound cylinder composed of a half-cylinder of birefringent material and a half-cylinder of glass about their common cylindrical axis. The cylinder is placed between a pair of plano-concave sections, which match the curvature and materials of the cylinder. The ordinary refractive index of the birefringent half-cylinder section is matched to that of the isotropic glass half-cylinder, which limits the changes in exit beam angular divergence to only one of the beams. A phase compensation block preceding the birefringent plano-concave section and the compound cylinder prevents the accumulation of optical phase between the two exit beams.

Abstract: A raster output scanning system is disclosed which utilizes a single light source, an electro-optical device and a beam-splitter to generate two partially overlapping light beams in order to scan one scan line in which the width of the scan line can be adjusted electronically. The two partially overlapping light beams in effect generate a resulting light beam. By changing the polarization factor of the electro-optical device, the intensities of the two light beams can be modified which in turn will change the width of the resulting light beam and as a result the spot size changes. By changing the spot size, the width of the scan line can be adjusted. Also, by changing the polarization factor, the position of the resulting light beam can be changed.