| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 398085000 | Filter | 21 |
| 20080267629 | OPTICAL RING NETWORK ARCHITECTURE - An optical ring network architecture including a number (N) of multi-add/drop filters, such as filters formed using symmetrical pairs of frequency routers. Each multi-add/drop filter is coupled to two other multi-add/drop filters using N−2 transmission media, such as optical fibers, to form a ring. The network also includes a number (N) of terminal stations associated with the multi-add/drop filters. A terminal station (p) is coupled with, and receives information from, its associated multi-add/drop filter (p) through a single optical fiber. In addition, the terminal station p is coupled with, and transmits information in a first direction around the ring to, a multi-add/drop filter p+1 through a single optical fiber. Communications from terminal station p to each other terminal station in the first direction are assigned one of N−1 wavelengths such that no two wavelengths on a given optical fiber are associated with communications between terminal stations in the same direction. Moreover, all wavelengths on a given optical fiber may be associated with a communication between terminal stations in either the first or second direction. As a result, each terminal station can communicate with each other terminal station simultaneously using wavelength division multiplexing and N−1 wavelengths. The network may also be bi-directional such that each terminal station p is coupled with, and transmits information in a second direction opposite the first direction to, a multi-add/drop filter p−1 through a single optical fiber. | 10-30-2008 |
| 20090028567 | Method and Device for Tunable Optical Filtering - An optical device includes an optical splitter having an input port, a first output port, a second output port and a resonant structure including at least a resonator, the optical splitter being adapted to receive at the input port a WDM optical signal and to output at the first and second output ports, respectively, a first and a second portion of the optical signal, the second portion including the channels lying on a sub-grid of optical frequencies spaced by an integer multiple of the WDM frequency spacing; an optical combiner having a first input port, a second input port, an output port and adapted to receive at the first and second input ports, respectively, the first and the second portions and adapted to output them at said output port; a first optical path optically connecting the first output port of the optical splitter to the first input port of the optical combiner so as to propagate the first portion; a second optical path optically connecting the second output port of the optical splitter to the second input port of the optical combiner so as to propagate the second portion; and an optical filter optically coupled to the second optical path, wherein the optical combiner includes at least one resonant structure including at least a resonator. | 01-29-2009 |
| 20090041463 | Systems And Methods For Providing A Three-Port Reconfigurable Optical Add-Drop Multiplexer With An Improved Edge Profile And Add/Drop Flexibility - The technology described herein provides a low-cost three-port reconfigurable optical add-drop multiplexer (ROADM) with an improved edge profile and add/drop flexibility. The technology described herein further provides a tunable spectral filter utilizing two sets of gratings and lenses and a two-axis micro-electro-mechanical system (MEMS) mirror with a selectively shaped cut-out disposed within the middle of the collimated optical path. | 02-12-2009 |
| 20090220242 | OPTICAL ADDING AND DROPPING DEVICE AND OPTICAL TRANSMISSION APPARATUS - An optical adding and dropping device includes a drop section including an input port and having a through port and a plurality of drop ports set as output ports, a first multiplexer adapted to multiplex light from the through port and light from a plurality of add ports, and a spectrum foot removing section provided on the input side of the first multiplexer and adapted to remove a foot of a spectrum of light to be inputted from the add ports to the first multiplexer. The optical adding and dropping device can be configured at a low cost while it has adding and dropping functions. | 09-03-2009 |
| 20100008672 | Optical Add/Drop Multiplexer Including Reconfigurable Filters and System Including the Same - An optical add/drop multiplexer (OADM) and system incorporating the same for maintaining loading of WDM channels with loading signals or information signals when signals are added or dropped. The OADM may include reconfigurable band pass filters having a transmittance characteristic controllable using a command signal. Selective filtering of loading signals and/or information signals received from branch and trunk paths allows an output WDM signal including information signals on utilized channels and loading signals on all unutilized channels. | 01-14-2010 |
| 20100183312 | METHOD AND DEVICE FOR HITLESS TUNABLE OPTICAL FILTERING - The method for filtering an optical signal comprising a plurality of channels lying on a grid of optical frequencies equally spaced by a frequency spacing and occupying an optical bandwidth, comprises: a) operating an optical filter comprising a plurality of resonators each having a respective free spectral range, wherein a first resonator of the plurality is optically coupled to the optical signal and the remaining resonators are optically coupled in series to the first resonator, so that a respective resonance of each one of the plurality of resonators falls within a first frequency band having bandwidth less than or equal to 15 GHz; b) operating the optical filter so as to obtain a separation between any resonance of at least one resonator falling within the optical bandwidth with respect to a resonance of at least another different resonator nearest to the any resonance, the separation being greater than or equal to 150 GHz and no more than 1 THz; c) tuning all the resonators of the optical filter so as to move all respective resonances of the resonators by a respective frequency interval greater than the frequency spacing while maintaining a distance between the any resonance of the at least one resonator with respect to the nearest resonance of the at least another different resonator not less than 150 GHz and no more than 1 THz; and d) operating the optical filter so that a further respective resonance of each one of the plurality of resonators falls within a second frequency band, different from the first frequency band, having bandwidth less than or equal to 15 GHz. A corresponding device for filtering an optical signal is disclosed. | 07-22-2010 |
| 20100284696 | OPTICAL MULTIPLEXER - A scalable reconfigurable (or tunable) optical add/drop multiplexer (SROADM) is disclosed. The SROADM includes a pair of acoustic optic tunable filters (AOTF) and a wavelength blocker (WB). A first input port receives an initial wavelength division multiplexer (WDM) optical signal including to-be-dropped optical signal(s). A second input port(s) receives optical signal(s) to be added, which has the same wavelength(s) as that optical signal(s) to be dropped. In one embodiment, the WB is connected to the AOTFs through free space coupling. In another embodiment, the coupling is achieved by optical fiber fusion splicing. The latter method has advantage of using commercially available products and easier assembly while a more compact size is achievable by the free space coupling. The device is scalable in terms of number of add/drop ports and capacity to process any number of wavelength channels. | 11-11-2010 |
| 20110038636 | Optical Add/Drop Multiplexer - An optical add/drop multiplexer includes a first optical coupler receiving an optical signal including a plurality of multiplexed wavelengths, a wavelength blocker receiving the optical signal from the first optical coupler, and blocking at least one wavelength of the plurality of multiplexed wavelengths, a first wavelength selective switch, having one input port receiving the outputted optical signal from the first optical coupler and a plurality of output ports, demultiplexing a plurality of arbitrarily selected multiplexed wavelengths from the received optical signal, a second wavelength selective switch, having a plurality of input ports, each input port receiving a different optical signal and one output port, multiplexing a plurality of arbitrarily selected wavelength signals on the plurality of input ports, and a second optical coupler receiving the optical signal output from the wavelength blocker and multiplexed wavelength signal from the second wavelength selective switch. | 02-17-2011 |
| 20110064412 | NOISE REDUCTION IN OPTICAL COMMUNICATIONS NETWORKS - An optical network node for an n-channel dense wavelength division multiplexing (DWDM) optical communications network, includes an add path for adding an n-channel wavelength multiplex onto the network. The add path has an n-channel signal combiner for combining the n signal channels. An optical amplifier amplifies an output of the signal combiner. A multichannel wavelength selective filter with variable-per-channel attenuation filters out noise from the amplifier on a channel which carries no content to be added to the network, and controls amplitude of signals in channels to be added to the network. An add coupler couples the add path to the network. | 03-17-2011 |
| 20120008958 | METHOD AND DEVICES FOR AUTOMATIC TUNING IN WDP-PON - A system and method in a wavelength division multiplexing passive optical network is provided. A multiplexed optical downstream signal is transmitted from an optical line terminal to a passive distribution node. The signal is demultiplexed into a plurality of optical sub-signals. A sub-signal is transferred to an optical network termination. The received at least one sub-signal is identified. An optical wavelength of an upstream optical signal is set as a function of a predefined relationship between an optical wavelength of the received at least one sub-signal and the optical wavelength of the upstream signal. The upstream signal is transmitted to the optical line terminal via the passive distribution node. | 01-12-2012 |
| 20120163825 | RECONFIGURABLE OPTICAL ADD-DROP MULTIPLEXER - A reconfigurable optical device including input and output ports, and add or drop ports, has a high degree of flexibility such that any wavelength channel from any optical signal introduced through the add ports may be added to any of the optical signals transmitted through the output ports. In addition, any wavelength channel from any optical signal received through the inputs ports may be dropped through any of the drop ports. Furthermore, the optical device is configurable to allow the same wavelength channel from two different optical signals supplied respectively through any two inputs ports to be simultaneously directed to two different drop ports. | 06-28-2012 |
| 20120189310 | BANDWIDTH ADJUSTABLE BANDPASS FILTER - An apparatus comprising a Mache-Zehnder interferometer. The Mache-Zehnder interferometer comprises: a 1×2 optical splitter having an optical input, a 2×2 optical coupler having first and second optical outputs, two optical waveguide arms end-connecting each optical output of the 1×2 optical splitter to a corresponding optical input of the 2×2 optical coupler, a variable optical phase shifter on one of the waveguide arms and a plurality of optical resonators, each optical resonator being controllably coupled along one of the optical waveguide arms. An optical path length between the optical input of the 1×2 optical coupler and the first optical output of the 2×2 optical coupler is substantially the same via the first optical waveguide arm and the second optical waveguide arm when the optical resonators are decoupled from the optical waveguide arms. | 07-26-2012 |
| 20120189311 | OPTICAL TRANSMISSION METHOD AND APPARATUS USING OFDM - In order to achieve a higher spectral efficiency of OFDM sub-bands, optical signals using orthogonal frequency division multiplexing are transmitted through an optical network in the form of a continuous waveband optical signal. An optical add/drop multiplexer ( | 07-26-2012 |
| 20120207479 | OPTICAL DEVICE WITH REDUCED THERMAL TUNING ENERGY - An optical device that includes multiple optical modulators having target operating wavelengths that are distributed over a band of wavelengths and actual operating wavelengths is described. For example, the target operating wavelengths of adjacent optical modulators may be separated by a wavelength increment. Moreover, because of differences between the actual operating wavelengths and the target operating wavelengths of the optical modulators, tuning elements may be used to tune the optical modulators so that the actual operating wavelengths match corresponding carrier wavelengths in a set of optical signals. Furthermore, control logic in the optical device may assign the optical modulators to the corresponding carrier wavelengths based at least on differences between the carrier wavelengths and the actual operating wavelengths, thereby reducing an average tuning energy associated with the tuning elements. | 08-16-2012 |
| 20120328297 | SUPERIMPOSED SIGNAL DETECTION CIRCUIT AND OPTICAL NODE EQUIPMENT - A superimposed signal detection circuit detects a signal superimposed on an optical signal in a WDM system. The superimposed signal detection circuit includes: an optical filter having wavelength-dependent loss to filter a plurality of optical signals on which a corresponding superimposed signal is superimposed by frequency modulation; a photo detector to convert the plurality of optical signals filtered by the optical filter into an electric signal; and a detector to obtain information indicated by the superimposed signal respectively superimposed on the plurality of optical signals from the electric signal obtained by the photo detector. | 12-27-2012 |
| 20130011141 | METHOD AND DEVICE FOR INSERTING/EXTRACTING OPTICAL SUBBAND INTO MULTIBAND OPTICAL OFDM SIGNAL - A device for inserting/extracting at least one optical subband into an optical channel consisting of a plurality of optical subbands. The device includes an extraction means that is capable of extracting a first optical subband belonging to the optical channel, a suppression means that is arranged so as to obtain a filtered optical channel from the optical channel wherein at least one second subband is suppressed, and a coupling means that is capable of inserting a replacement optical subband in place of the second subband in the filtered optical channel so as to obtain a modified optical channel. The device moreover relates to an optical insertion/extraction switcher, using one or more insertion/extraction devices, and to the corresponding insertion/extraction methods. | 01-10-2013 |
| 20130142517 | Controllable Optical Add/Drop Multiplexer - The invention relates to a method for operating a controllable selective optical add/drop channel for a fiber-optic communication system provided with 2 | 06-06-2013 |
| 20140341583 | Reconfigurable Optical Add-Drop Multiplexer - A reconfigurable optical device including input and output ports, and add or drop ports, has a high degree of flexibility such that any wavelength channel from any optical signal introduced through the add ports may be added to any of the optical signals transmitted through the output ports. In addition, any wavelength channel from any optical signal received through the inputs ports may be dropped through any of the drop ports. Furthermore, the optical device is configurable to allow the same wavelength channel from two different optical signals supplied respectively through any two inputs ports to be simultaneously directed to two different drop ports. | 11-20-2014 |
| 20150318948 | System and Method for Monitoring Filters in an Optical Add-Drop Multiplexer - A system and method for monitoring one or more filter configurations in an optical add-drop multiplexer for detecting faults in the filter configurations. A monitoring system is configured to filter the outputs of the filter configurations using one or more of a plurality of predetermined filter shapes corresponding to intended add, through, drop and/or branch through channels. The monitoring system detects power passing through the filter shapes to detect faults in the filter configurations. | 11-05-2015 |
| 20160142171 | SIGNAL DETECTION CIRCUIT AND OPTICAL TRANSMISSION EQUIPMENT - A signal detection circuit includes: a first optical filter configured to filter an optical signal carrying a frequency modulated signal with a first transmission band; a second optical filter configured to filter the optical signal with a second transmission band; a first photo detector configured to convert the output light of the first optical filter into a first electrical signal; a second photo detector configured to convert the output light of the second optical filter into a second electrical signal; a difference circuit configured to output a signal representing a difference between the first electrical signal and the second electrical signal; and a detector configured to detect the frequency modulated signal based on the output signal of the difference circuit. | 05-19-2016 |
| 20160173222 | WAVELENGTH DIVISION MULTIPLEXING MODULE | 06-16-2016 |
