Multiple optical switches using refractive optics
Granted: March 29, 2005
Patent Number:
6873757
A mechanical optical switch includes a port, a first lens element, a free beam path, and a beam guiding element. The port is adapted to receive a first group of optical fibers. The first lens element has an optical axis and is positioned in front of the first group of optical fibers. The free beam path couples light beams from a second group of optical fibers to the first lens element such that the light beams are coupled to the first group of optical fibers in a first coupling…
Tap outlet collimator
Granted: March 22, 2005
Patent Number:
6870988
This invention discloses an optical collimator that includes a built-in tap-out projection optical arrangement for projecting a portion of an incoming beam to a tap-out beam-transmission fiber. In one of the preferred embodiments, the built-in tap-out projection optical arrangement further includes a front surface having an incline angle for projecting a portion of an incoming beam to a tap-out beam transmission fiber. In another preferred embodiment, the built-in tap-out projection…
Optical fiber amplifier with error correction
Granted: March 8, 2005
Patent Number:
6865017
Methods and apparatus for amplifying a signal are provided. In one aspect, a method is provided for amplifying an optical signal using an EDFA and includes amplifying an input signal using an EDFA producing an amplified output signal; measuring a pump residual power component of the amplified output signal, and using the measured pump residual power component to adjust a performance of the EDFA.
Dispersion compensation using resonant cavities
Granted: February 22, 2005
Patent Number:
6859320
Multi-stage, all-pass optical filters used to make low-loss, multi-channel dispersion compensation modules are disclosed. The all-pass optical filters can be ring resonators in waveguides, Gires-Tournois Interferometers (GTIs) in free space form, and the like. The coupling constants and circulating path lengths may also be distinctively varied in each of the series of GTIs, tuning the net dispersion spectrum of the GTI set, such that the sum of the dispersions from the series of GTI's…
Method for using length dispersion in an etalon to approximate target resonant frequencies
Granted: February 15, 2005
Patent Number:
6856443
Methods for using a length dispersion of an etalon to approximate target resonant frequencies. Length dispersion usage in the present invention includes, for example, determining the impact of a length dispersion of an etalon on resonant frequencies of the etalon and may involve, for example, selection of one a more of a refractive index step, a number of layers, and a layer thickness of one or both dielectric stacks of the etalon in consideration of length dispersion. A featured method…
System and method for optical multiplexing and/or demultiplexing
Granted: January 25, 2005
Patent Number:
6847450
Improved methods and systems for routing and aligning beams and optical elements in an optical device include a multiplexing device and/or a demultiplexing device, which includes an optical alignment element (OAE). The OAE can be configured to substantially compensate for the cumulative alignment errors in the beam path. The OAE allows the optical elements in a device, other than the OAE, to be placed and fixed in place without substantially compensating for optical alignment errors. The…
System and method for optical multiplexing and/or demultiplexing
Granted: January 18, 2005
Patent Number:
6844932
Improved methods and systems for routing and aligning beams and optical elements in an optical device include a multiplexing device and/or a demultiplexing device, which includes an optical alignment element (OAE). The OAE can be configured to substantially compensate for the cumulative alignment errors in the beam path. The OAE allows the optical elements in a device, other than the OAE, to be placed and fixed in place without substantially compensating for optical alignment errors. The…
Optical isolator
Granted: January 4, 2005
Patent Number:
6839170
An optical system provides reflection-type isolation, and may include variable optical attenuation and/or a tap monitor. The optical system may include an optical isolator with a beam splitter such as a walk-off plate, a focusing element such as a GRIN lens, a combiner comprising two birefringent wedges and a non-reciprocal rotating device such as a Faraday rotator, a compensation device, and a reflector. The Faraday rotator may be variable to provide variable attenuation. The reflector…
Three-port PM circular having isolation function
Granted: December 28, 2004
Patent Number:
6836575
An optical device includes non-reciprocal combination-device and a polarizer. The non-reciprocal combination-device has a principal direction and a reverse principal direction. The non-reciprocal combination-device includes a first birefringent wedge, a second birefringent wedge, and a non-reciprocal rotating element. The polarizer receives a first light signal from the second birefringent wedge traveling in the principal direction and transmits a second light signal to enter the second…
Optical subassembly with port configuration
Granted: December 28, 2004
Patent Number:
6836590
An optical subassembly utilizes a core with a first, second, and third faces. The first and second faces are coupled, non-parallel, and non-co-planar for changing a path of a beam, and their intersection defines an axis. Filters are coupled to the third face. The light path traverses between the first or second face and each filter such that, at each filter, no portion of the light path interferes with any other portion of the light path. The light path also traverses the core in a…
Depolarizer
Granted: November 16, 2004
Patent Number:
6819810
An optical depolarizer includes a non-reciprocal combination-device, a birefringent block, and a reflector. The non-reciprocal combination-device has a principal direction and includes a first birefringent wedge, a second birefringent wedge, and a non-reciprocal rotating element. The non-reciprocal rotating element can be a Faraday rotator. The birefringent block is optically coupled to the second birefringent wedge. The reflector is optically coupled to the birefringent block. The…
Gires-Tournois interferometer with faraday rotators for optical signal interleaver
Granted: September 28, 2004
Patent Number:
6798551
A GTIFR interferometer, for use in an interleaver or in a deinterleaver, wherein the GTIFR interferometer includes a Gires-Toutnois interferometer with a 45 degree Faraday rotator between the mirrors of the Gires-Tournois interferometer and further includes a 22.5 degree Faraday rotator in the light path to the Gires-Tournois interferometer and an interleaver or deinterleaver that contains one GTIFR. A dispersion compensated GTIFR interleaver includes a second Gires-Tournois…
Wavelength interleaver
Granted: August 10, 2004
Patent Number:
6775435
This invention discloses an optical interleaver that includes a first collimating lens for collimating an input optical signal into collimated beams and a second collimating lens for focusing the collimated parallel beams into an output optical fiber. The interleaver further includes a phase delay difference generating means for generating a phase-delay difference between portions of the collimated parallel beams for generating an interference in the second collimating lens for…
Method and system for providing an optical circulator
Granted: July 13, 2004
Patent Number:
6762879
In another aspect, the invention provides a closed loop optical circulator including a first crystal for splitting an input light signal into two components, a second crystal for deflecting the two components received from the first crystal in a direction if the two components have a first polarization, a third crystal for deflecting the two components received from the second crystal in an opposite direction if the two components have the first polarization, and a fourth crystal for…
Multi-port circulator
Granted: June 15, 2004
Patent Number:
6751366
An extendable four-port circulator includes a middle birefringent crystal, a first birefringent crystal, a first non-reciprocal device, a second birefringent crystal, and a second non-reciprocal device. The first non-reciprocal device is coupled to the first birefringent crystal. The second non-reciprocal device is coupled to the second birefringent crystal. The middle birefringent crystal includes a first surface, a second surface, a third surface, and a fourth surface. The first…
Loop optical circulator
Granted: June 8, 2004
Patent Number:
6747797
A four-port loop optical circulator includes a first, a second, a third and a fourth optical ports for receiving optical beam therein. The circulator further includes a plurality of optical components. The optical components include a walk-off crystal for generating a vertical optical path displacement for a vertical polarized optical beam and for passing a horizontally polarized optical beam therethrough maintaining a same optical path. The optical components also include a vertical…
Leak detector for sealed optical devices
Granted: February 24, 2004
Patent Number:
6696296
This invention discloses a method for detecting a leak from a sealed optical device. The method includes steps of: A) injecting a target gas with no performance interference to the sealed optical device for leak detection followed by sealing the sealed optical device. B) placing the sealed device in a leak testing chamber and measuring a background level of the target gas in the leak testing chamber. C) heating the sealed device to a gas-expelling temperature for expelling the target gas…
Wavelength slicer for optical signal switching
Granted: February 3, 2004
Patent Number:
6687462
A wavelength slicing apparatus and method includes two filters having passbands offset from each other and from a signal channel. The offset passbands enhance transmission where they overlap and reduce transmission where they do not overlap such that transmission of optical signals in a neighboring channel is suppressed. A third filter having a passband centered on the signal channel frequency may be included to enhance optical signal isolation. Wavelength slicing techniques may be used…
WDM with optical interleaving for increased channel capacity
Granted: January 13, 2004
Patent Number:
6678476
A wavelength division multiplexing (WDM) apparatus and a WDM method are disclosed. The apparatus generally comprises an optical interleaver coupled to one or more WDM modules. Two or more interleaver modules may be cascaded together to expand the channel handling capacity. Alternatively, two or more WDM modules may be cascaded together to divide the even and odd channels into subsets. The interleaver interleaves a first signal, containing one or more odd channels and one or more even…
Tap output collimator
Granted: November 25, 2003
Patent Number:
6654518
This invention discloses an optical collimator that includes a built-in tap-out projection optical arrangement for projecting a portion of an incoming beam to a tap-out beam-transmission fiber. In one of the preferred embodiments, the built-in tap-out projection optical arrangement further includes a front surface having an incline angle for projecting a portion of an incoming beam to a tap-out beam transmission fiber. In another preferred embodiment, the built-in tap-out projection…
