Planar lightwave circuit variable optical attenuator
Granted: June 23, 2005
Application Number:
20050135728
The invention relates to a variable optical attenuator constructed as a Mach Zehnder planar lightwave circuit, particularly including a channel waveguide support structure for heat isolation and stress relief to reduce polarization dependent loss (PDL) and power consumption in the device. Power reduction trenches comprise longitudinal segments having small stress relief pillars of cladding material left in between them in the etching process. The waveguides of the MZI are supported by a…
Transimpedance amplifier with linearized transconductance feedback
Granted: June 16, 2005
Application Number:
20050128006
The invention relates to a feedback circuit for a transimpedance amplifier, which is typically used for converting an input current from a photodiode into an output voltage. The feedback circuit of the present invention linearizes the transconductance feedback, as the input current signal varies, by providing a constant current source for supplementing the DC feedback current through a bypass transistor, thereby reducing a variation in the low frequency cut off.
Polarization controlling elements
Granted: June 16, 2005
Application Number:
20050128380
The invention relates to a polarization compensating element (PCE) for a liquid crystal, e.g. liquid crystal on silicon (LCoS), display system manufactured using a linearly photo-polymerizable polymer (LPP) for orienting a photo-polymerizable liquid crystal polymer (LCP) film. To decrease the reflection, polarization conversion, and interference events in an LPP/LCP assembly the ?N birefringence value of the LCP material is minimized. Dielectric coatings are added at various locations…
Trim retarders incorporating negative birefringence
Granted: June 16, 2005
Application Number:
20050128391
The present invention relates to trim retarders used to compensate for residual birefringence created by liquid crystal display panels. In particular the present invention relates to a trim retarder with negative out-of-plane birefringence provided by a form birefringent multi-layer dielectric stack for compensating for retardances resulting from liquid crystal on silicon display panels.
Reflective illumination system
Granted: June 9, 2005
Application Number:
20050122575
This invention discloses a reflective illumination system for supplying an optical radiation beam along a folded path for illuminating a planar object. The system includes a radiation source, and two facing parabolic dish-shaped arrays of parabolic or dished reflectors. Divergent light received from the light source incident on a first of the arrays is reflected as a larger collimated beam comprising plural separated sub-beams. Each of the reflectors or facets from the first array…
Method and apparatus for orienting magnetic flakes
Granted: May 19, 2005
Application Number:
20050106367
Apparatus and related methods align magnetic flakes in a carrier, such as an ink vehicle or a paint vehicle to create optically variable images in a high-speed, linear printing operation. Images can provide security features on high-value documents, such as bank notes. Magnetic flakes in the ink are aligned using magnets in a linear printing operation. Selected orientation of the magnetic pigment flakes can achieve a variety of illusive optical effects that are useful for decorative or…
Transceiver guide rail with heat sink guide
Granted: May 12, 2005
Application Number:
20050100292
The latest 10 Gb/s optical transceivers include large heat sinks with heat dissipating fins or pins extending from an upper surface thereof, which can cause difficulties when the transceivers are passed through an opening of a faceplate onto the guide rail of a host device. Often the heat dissipating fins or pins will contact an edge of the faceplate opening causing a series of ratcheting impacts that can damage the fins or pins. Accordingly, the present invention provides a guide rail…
Dyed polymer coating for display panel
Granted: May 12, 2005
Application Number:
20050100690
An transmissive panel includes a polymer coating with a textured antireflective surface. Texturing of the surface is achieved in a variety of fashions. In some embodiments the polymer coating is embossed after application to the panel. In other embodiments, the polymer coating is solvent-based and develops a textured surface as a result differential shrinkage. In yet other embodiments, an aerosol of solvent-based polymer precursor is applied to the surface as a combination of…
HIGH-RESOLUTION PROJECTION DISPLAY SYSTEM
Granted: April 28, 2005
Application Number:
20050088629
An image display system uses a polarizing beam splitter to direct light from a lamp to multiple spatial light modulators. The spatial light modulators (“SLM”) each generate an image portion, which are stitched together on a display screen to obtain a high resolution image. In a particular embodiment, image portions from two conventional SLMs, each controlling about two million pixels, are stitched together to form an image having about four million pixels. In another embodiment, two…
Wavelength monitor
Granted: April 28, 2005
Application Number:
20050088658
A wavelength monitoring device for monitoring a beam of light is disclosed having a beam splitter, with opposing first and second spaced apart faces, for receiving optical radiation from the beam of light to be monitored. In operation the first face reflects a first portion of the optical radiation to a first photodiode. The second face includes a grating for reflecting a second portion of the optical radiation to the first photodiode. The grating also reflects a third portion of optical…
Optical fiber pigtail assembly
Granted: April 7, 2005
Application Number:
20050074217
A fiber tail assembly (FTA) with a micro-lens formed in the fiber tip is used to couple the laser light out of the package and along the fiber. The FTA is soldered at two points where metallized bands are deposited on the fiber pigtail, one at a fiber mount near the diode where it can be soldered into alignment with the laser diode, and two at the snout which forms a feed through the housing and seal for the package. Typically, the FTA is metallized along its entire length within the…
Shielded label package and method of making the same
Granted: March 31, 2005
Application Number:
20050067830
A plurality of die cut labels formed on a label substrate attached on the surface of a carrier for the die cut label substrate. A protective cover, preferably but not necessarily formed of transparent material, is adhesively secured over the die cut label substrate by way of a dry peel adhesive deposited on the surface of the die cut label substrate. The dry peel adhesive is such that when the protective cover is removed from the die cut label substrate, no tacky adhesive residue remains…
Folding converging light into a lightpipe
Granted: February 17, 2005
Application Number:
20050036203
The present invention relates to a folded front end unit used in a light engine of a projection display device. The front end unit comprises a light source for generating a beam of light, and a lightpipe for providing spatial uniformity to the beam of light. Polarization-dependent front end units include polarization beam splitters for separating the light into orthogonally polarized sub-beams, and a polarization rotating element, e.g. a waveplate, for rotating the polarization of one of…
Flake for covert security applications
Granted: February 17, 2005
Application Number:
20050037192
Covert flakes having one or more symbols and/or a selected shape are used in a composition, such as ink or paint, to provide a covert security feature to an object. In some embodiments the composition includes base pigment, and the covert flakes are covert pigment flakes that match the visual characteristics of the base pigment. In another embodiment, clear covert flakes are mixed in the carrier with base pigment. In another embodiment, clear covert flakes are mixed in a varnish base to…
Optical performance monitor
Granted: February 10, 2005
Application Number:
20050031259
An apparatus for monitoring an input optical signal at a plurality of distinct optical frequencies is disclosed wherein a demultiplexing arrayed waveguide grating (AWG) having a plurality of M>1 Vernier input ports is disposed between an optical switch and a photodiode array coupled to the output ports of the AWG. In operation, the optical switch sequentially provides the input optical signal into each of the Vernier ports, and signals detected by photodiodes are stored in a memory…
Planar circuit optimization
Granted: February 10, 2005
Application Number:
20050031968
The present application relates to a method of fabricating planar circuits using a photolithographic mask set, to the photolithographic mask set, and to a planar circuit fabricated with the photolithographic mask set. The instant invention involves separating a photolithographic mask into two parts, namely, a master mask and one or more slave masks. The master mask and the one or more slave masks form a photolithographic mask set that is used iteratively to fabricate the planar circuits.…
Coating for forming a high definition aperture
Granted: February 3, 2005
Application Number:
20050024745
An optical thin film stack for a dark aperture is deposited using thermal ion-assisted deposition (“IAD”). The IAD provides an energetic deposition of chromium and chromium oxide that results in a dark mirror optical thin film stack with superior etch properties. Edge definition is improved, and the edge profile is controllable by the selection of IAD parameters. An in situ IAD cleaning process can be used to clean the substrate sufficiently so that an intermediate adhesion layer of…
Polarization compensated optical tap
Granted: February 3, 2005
Application Number:
20050025427
A polarization compensated planar waveguide branch is disclosed having a planar optical trunk waveguide for transporting a linearly un-polarized optical signal having TE and TM modes. A planar optical branch waveguide, capable of supporting TE and TM modes is optically coupled to the trunk waveguide such that at least a portion of an optical signal propagating within the trunk waveguide will couple into the branch waveguide with an undesired imbalance, having stronger TM mode coupling…
Doped absorption for enhanced responsivity for high speed photodiodes
Granted: January 27, 2005
Application Number:
20050017317
A photodiode with a semiconductor intrinsic light absorption layer has at least one p-doped light absorption layer or an n-doped light absorption layer, and preferably both. The diode also has a cathode electrode and an anode electrode electrically coupled with the p-doped light absorption layer or the n-doped light absorption layer.
Dynamic optical demultiplexer/multiplexer formed within a PLC
Granted: January 27, 2005
Application Number:
20050018965
A demultiplexer/multiplexer is disclosed wherein an arrayed waveguide grating having a reflector at an end includes selectable signal path blockers. The arrayed waveguide device has a common input/output port for launching radiation in the form of an input signal having n wavelengths therein and for receiving back via the reflector at the input/output port a selected channel of the input signal. In operation a multiplexed signal have n channels is launched therein and a selected channel…
