Articulated MEMs structures
Granted: October 7, 2008
Patent Number:
7432629
The present invention relates to an articulated micro-electro-mechanical (MEMS) device, which is constructed in such a way as to enable several of the devices to be closely packed together, i.e. high fill factor, for redirecting specific wavelengths of light from a dispersed optical signal to different output ports. The articulated MEMS device includes multiple pivotally connected sections that are pivotable about two perpendicular axes for limiting the amount of dynamic cross-talk as…
Two-panel color management system
Granted: September 30, 2008
Patent Number:
7429111
The invention provides a two-panel color management system for projection display applications, wherein color sequencing is accomplished using achromatic beam switching and static color separation. In a preferred embodiment, a liquid-crystal polarization switch alternates a polarization of an input light beam between two orthogonal states. A polarization beam splitter directs the beam comprising three primary color components alternately along a first and second paths, wherein first and…
Shared optical performance monitoring
Granted: September 16, 2008
Patent Number:
7426347
An apparatus for shared optical performance monitoring (OPM) is provided. A wavelength sensitive device receives light at an input port and routes it wavelength selectively to a set of output ports. To perform optical performance monitoring on the output ports, a monitoring component of each output signal is extracted, and these monitoring components are then combined. A single OPM function is then performed on the combined signal. However, with knowledge of the wavelengths that were…
Spectrally resolved fast monitor
Granted: September 9, 2008
Patent Number:
7423804
A method and apparatus for monitoring spectral tilt uses an arrayed waveguide grating (AWG) to separate a multiplexed optical signal having a plurality of wavelength channels into a plurality of sub-bands, where each sub-band spans a different wavelength range and includes more than one wavelength channel. A photodetector array is provided to measure the optical power in each of the sub-bands, while control electronics calculate spectral tilt of the multiplexed optical signal using the…
Electro-optic device
Granted: August 5, 2008
Patent Number:
7408693
The invention relates to an electro-optic modulator structure containing an additional set of bias electrodes buried within the device for applying bias to set the operating point. Thus the RF electrodes used to modulate incoming optical signals can be operated with zero DC bias, reducing electrode corrosion by electro-migration, galvanic, and other effects that can be present in non-hermetic packages. The RF electrodes are supported by a first surface of the electro-optic substrate,…
Apparatus and method for characterizing pulsed optical signals
Granted: July 29, 2008
Patent Number:
7405829
The coherent interference effect between two beam is used with one light beam delayed by a controllably variable time delay with respect to another analogous beam to obtain a convolutional profile of the oscillatory component of the interference amplitude as a function of the time delay, having a peak value representing the performance clearance between a zero-bit and a one-bit. The convolutional profile is represented by a diamond diagram (DD) of the interference amplitude, within the…
Injection seeding of frequency-converted Q-switched laser
Granted: June 24, 2008
Patent Number:
7391794
A non-linearly frequency-converted Q-switched laser is “injection seeded” with short pulses from another laser, called a seed laser. Radiation produced by the Q-switched laser is frequency converted in a non-linear process. The injection seeding can enhance peak power and frequency conversion efficiency while reducing damage to a non-linear medium used to frequency convert radiation generated by the Q-switched laser.
Illumination system using polarization conversion
Granted: June 17, 2008
Patent Number:
7387388
An apparatus and method is discloses for providing a substantially uniform, homogenous, polarized light. A beam of substantially un-polarized light is provided by a conventional light source. The un-polarized light is converted to at least four real images by using a light pipe and appropriate lensing. Each of the real images have a light region and one more dark regions at a first image plane. A portion of light from a light region in each real image is directed to one or more dark…
DC offset cancellation for a trans-impedance amplifier
Granted: May 6, 2008
Patent Number:
7368999
The invention relates to a DC offset cancellation circuit for a trans-impedance amplifier, which is typically used for converting an input current from a photodiode into an output voltage. The DC offset cancellation circuit utilizes the monitor current from a photodiode monitoring device to cancel the DC offset from the photodiode input current, enabling the conventional feedback circuit in the trans-impedance amplifier to be fully integrated.
Single spatial mode output multi-mode interference laser diode with external cavity
Granted: April 29, 2008
Patent Number:
7366210
The invention relates to a conventional broad-area laser having a single-mode output through the phenomenon of multimode interference (MMI) in step-index waveguides. Another aspect of the present invention relates to a very robust multi-mode compound cavity laser design that is fully defined by the geometry and the refractive index profile of the MMI region, which is quite insensitive to slight macro-scale refractive index variations due to manufacturing variation or temperature. As the…
Management of electrical cable installations in a building
Granted: April 29, 2008
Patent Number:
7366630
The installation of an electrical cable in a building and its subsequent testing are managed by first creating a computer database indicating the type of cable, the location where the cable is to be installed, the performance standard it should meet when installed in that location, and a test regimen to verify compliance with the performance standard. The database is then transferred into a hand held portable test instrument which is placed at the building site and connected to the cable…
Optical multiplexer
Granted: April 29, 2008
Patent Number:
7366364
An optical multiplexer includes a substrate into which are integrated a polarization rotator and a polarization coupler. The polarization coupler and the polarization rotator are in optical communication with each other.
Heat sink tab for optical sub-assembly
Granted: April 29, 2008
Patent Number:
7365923
The present invention relates to a heat sinking tab for dissipating heat directly from an optical sub-assembly (OSA) to a transceiver housing, within which the optical sub-assembly is located. The heat sinking tab includes a mounting plate for mounting on the rear end of a transistor outline (TO) can, and a finger for extending into contact or close proximity to the transceiver housing. The mounting plate also provides a stiffening plate for flexible conductors used to connect the OSA…
Laser transmitter capable of transmitting line data and supervisory information at a plurality of data rates
Granted: April 22, 2008
Patent Number:
7362972
An optical transmitter for sending supervisory data signals and line data signals as a composite optical signal through an optical fiber link is disclosed. The transmitter may take the form of a transmitter, transceiver or transponder and includes circuitry for receiving incoming line data bit rate information for varying and or controlling the modulation index by varying the supervisory carrier frequency amplitude in dependence upon the line data bit rate.
Staggered vertical comb drive fabrication method
Granted: April 15, 2008
Patent Number:
7357874
The invention relates to a method of fabrication of staggered vertical comb drive actuators with relaxed lateral alignment tolerances. A device layer of a wafer is first etched from a front side using a self-aligned two-layer mask to define interdigited fingers of both moving and stationary combs. A second etch step is used for vertically thinning one of the two sets of fingers by selectively removing their top portions. The front side of the wafer is then bonded to a carrier wafer. The…
Optical array with beam alignment feature
Granted: April 15, 2008
Patent Number:
7359053
An array of optical elements for processing a spatially dispersed optical beam including monitoring optical elements for determining the position of the optical beam in the array is disclosed. The monitoring optical elements have a width that varies in ay direction normal to the array axis, enabling the determination of the beam position across the monitoring elements in both x and y directions. The monitoring optical elements are preferably disposed in the end portions of the array for…
Laser burst boosting method and apparatus
Granted: April 1, 2008
Patent Number:
7352784
Methods and apparatus for managing thermal loads on a laser gain medium and for boosting the output power of a diode pumped laser are disclosed. The short-term average pumping power to the gain medium is increased, to provide a burst of pumping energy to the laser gain medium. A subsequent short-term reduction in the average pumping power then allows the gain medium to cool to a desired state steady level. The average pumping power is then increased to maintain this steady state level…
Tunable optical add/drop multiplexer
Granted: April 1, 2008
Patent Number:
7352928
The tunable add/drop multiplexer including a tiltable mirror, a fixed thin film filter, and first and second retro-reflector elements for redirecting express channels back out an input/output port and for redirecting drop channels back out an add/drop port, respectively.
Image display device
Granted: March 25, 2008
Patent Number:
7347561
A color management system for use with projection displays includes, for example, two or more analyzers positioned to receive light beams as they are emitted from the panels of a color management system. The analyzers are positioned to receive the light beams directly from the image assimilators before the light has passed through another optical element such as a light combiner. The analyzers are configured for producing filtered light outputs with improved contrast relative to the…
Two-panel liquid-crystal-on-silicon color management system
Granted: March 25, 2008
Patent Number:
7347562
A two-panel projection display system includes a color wheel having color filter segments that transmit light having a secondary color, namely cyan, magenta, and yellow, made up of two primary colors. A primary color separator, such as a second color wheel, a transflective dichroic beamsplitter, or a color-sensitive polarizing switch separates the secondary color beam into a first polarized primary color beam and a second polarized primary color beam, which are directed to first and…
