| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 359325000 | OPTICAL DEMODULATOR | 32 |
| 20080225380 | Delay line interferometer having a movable mirror - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-18-2008 |
| 20080225381 | Delay line interferometer having a stepped delay element - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-18-2008 |
| 20080231941 | Optical receiver having FSR phase compensation - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-25-2008 |
| 20080239465 | DELAY-LINE DEMODULATOR AND METHOD OF ADJUSTING A PHASE SHIFT IN THE DEMODULATOR - In a method of phase adjustment for the demodulator | 10-02-2008 |
| 20080239466 | Device and Method for the Demodulation Electromagnetic Wave Fields - A new pixel in semiconductor technology comprises a photo-sensitive detection region ( | 10-02-2008 |
| 20080247033 | Device and Method for the Demodulation of Modulated Electric Signals - A demodulation device ( | 10-09-2008 |
| 20090059351 | DEMODULATOR SYSTEM AND METHOD USING MULTILEVEL DIFFERENTIAL PHASE SHIFT KEYING - A demodulator and demodulation method includes an optical coupler configured to receive an input signal. The optical coupler couples the signal to an even number of branches. Each branch including at least one interferometer configured to split, combine and interfere with an optical signal from one of within the branch or from another branch. A common optical delay is disposed on one of every two branches between the optical coupler and the interferometer of the branch. | 03-05-2009 |
| 20090097101 | DELAY-LINE DEMODULATOR - Problem to be Solved To provide a delay-line demodulator of which the divergence amount of polarization is reduced. | 04-16-2009 |
| 20090135473 | MODIFIED MICHELSON DELAY LINE INTERFEROMETER - In an optical etalon with a fixed FSR determined by the cavity length, the time delay is adjusted by an etalon surface coating. The proper cavity length is chosen to achieve a desired FSR, and the coating is independently selected to obtain a desired time delay. | 05-28-2009 |
| 20100046064 | DELAY DEMODULATION DEVICES - A delay demodulation device, which reduces chip size and polarization dependent frequency (PDf), is provided. The delay demodulation device comprises: an input waveguide, which receives DQPSK signals; a Y-shape waveguide, which splits the input waveguide; a first Mach-Zehnder interferometer; and a second Mach-Zehnder interferometer. Both end of two arm waveguides of first Mach-Zehnder interferometer and both ends of two arm waveguides of second Mach-Zehnder interferometer are angled toward the center portion of a Planar Lightwave Circuit (PLC). Because of the angle, the length of the two arm waveguides of the first Mach-Zehnder interferometer and the length of the two arm waveguides of the second Mach-Zehnder interferometer in Z-direction can be shortened, and input couplers and output couplers of the Mach-Zehnder interferometers in Z-direction can be shortened as well. The area occupied by the Mach-Zehnder interferometers is also reduced. | 02-25-2010 |
| 20100053731 | DELAY DEMODULATION DEVICES - Delay demodulation devices with optimized temperature and pressure distribution on a Planar Lightwave Circuit (PLC) are provided. The delay demodulation device | 03-04-2010 |
| 20100067098 | METHODS TO CONTROL PHASE SHIFTS OF DELAY DEMODULATION DEVICES - The present invention provides methods to control phase shift of delay demodulation devices to reduce Polarization Dependent wavelength (PDλ) to be less than, for example, 0.5 GHz (i.e. 0.004 nm). The method to control phase shift in a Planar Lightwave Circuit (PLC) for demodulating Differential Quadrature Phase Shift Keying (DQPSK) comprising two Mach-Zehnder interferometers, each having two arm waveguides and heaters placed on the two arm waveguides, the method comprising the steps of: (first step) supplying electricity to at least one predetermined heater on the two arm waveguides of each Mach-Zehnder interferometer such that Polarization Dependent wavelength (PDλ) is reduced as electricity is supplied to the predetermined heaters; (second step) inserting a half-wave plate in the two arm waveguides of each Mach-Zehnder interferometer after PDλ is reduced in the first step; (third step) supplying electricity to the predetermined heater on the at least one of the two Mach-Zehnder interferometers used in the first step to control phases of the DQPSK signals after the half-wave plates are inserted. | 03-18-2010 |
| 20100073760 | DELAY-LINE DEMODULATOR - A delay-line demodulator for demodulating a differential quadrature phase shift keying (DQPSK) signal is provided. The demodulator includes two Mach-Zehnder interferometers individually comprising two waveguides having different lengths therebetween and through which a light signal branched from the DQPSK signal propagates, respectively. A phase of the light signal propagating at one of the waveguides is delayed as compared to a phase of the light signal propagating at another one of the waveguides, wherein a divergence amount of polarization is adjusted by driving sets of heaters that are facing each other and sandwiching a half wavelength plate therebetween. | 03-25-2010 |
| 20100085630 | DEMODULATOR - A demodulator and method are provided. The demodulator for demodulating an optical signal, includes a splitter that splits a differential phase modulation signal into a first split light component and a second split light component, couples the first split light component to a first optical path and the second split light component to a second optical path, a first medium disposed on the first optical path, a second medium disposed on the second optical path and having a refractive index different from that of the first medium, and a combiner that combines the first split light component that has passed through the first medium and the second split light component that has passed through the second medium, wherein one of the first split light component and the second split light component is delayed in relation to the other. | 04-08-2010 |
| 20100128342 | Coherent Demodulation with Reduced Latency Adapted for use in Scanning Probe Microscopes - A signal demodulator and the method of using the same in a scanning probe microscope or the like to provide a feedback path with reduced latency are disclosed. The demodulator includes an input port, a first mixer and a first integrator. The input port receives an input signal having a frequency component at a signal frequency. The input signal is characterized by a signal amplitude at that frequency. The first mixer mixes the input signal with a first local oscillator signal at the signal frequency to generate a first mixed signal. The first integrator integrates the first mixed signal for an integer number of periods of the signal frequency to provide a first output signal. | 05-27-2010 |
| 20100284059 | DEMODULATOR - A demodulator includes a splitter, a first dielectric substance, and a combiner. The splitter splits a differential phase shift keying optical signal into a first light beam and a second light beam and outputs the first light beam to a first optical path and the second light beam to a second optical path. The first dielectric substance is disposed in the first optical path and has a refractive index higher than the average refractive index of the second optical path. The combiner combines the first light beam and the second light beam and causes the beams to interfere with each other. The difference in length between the first and second optical paths and the refractive index of the first dielectric substance are set such that the first light beam is delayed by one bit with respect to the second light beam. | 11-11-2010 |
| 20110170171 | OPTICAL DIFFERENTIAL PHASE-SHIFT KEYED SIGNAL DEMODULATOR - A phase-shift keyed signal demodulator is disclosed including a filter positioned to receive an input beam, a first photodiode positioned to receive light reflected from the filter, and a second photodiode positioned to receive light transmitted through the filter. A difference between outputs of the first and second photodiodes is interpreted to determine a data value encoded in the input beam. In another embodiment N filters receive inputs from a splitter and include transmission functions offset from one another. N pairs of photo diodes receive the transmitted and reflected beams from each filter and a decoder converts the outputs of the pairs of photodiodes to one or more data symbols. | 07-14-2011 |
| 20110176200 | Delay-Line-Interferometer for Integration with Balanced Receivers - This invention provides a DPSK demodulator and a DQPSK demodulator. Both of the demodulators are based on polarization delay-line interferometers. They can be integrated with photodetectors in fiber-optic communication systems. The demodulators consist of polarization beam shifter, polarization beam splitter and wave plates. Coupling of the demodulators with photodetectors can be through free space or fibers. Time delay generated in the interferometer can be controlled with a phase shifter, using either thermal, piezoelectric, mechanical or electrical means. Examples of phase shifter using a piezo bender and an actuator respectively are also disclosed. | 07-21-2011 |
| 20110261437 | Delay-Line-Interferometer for Integration with Balanced Receivers - This invention provides a DPSK demodulator and a DQPSK demodulator. Both of the demodulators are based on polarization delay-line interferometers. They can be integrated with photodetectors in fiber-optic communication systems. The demodulators consist of polarization beam shifter, polarization beam splitter and wave plates. Coupling of the demodulators with photodetectors can be through free space or fibers. Time delay generated in the interferometer can be controlled with a phase shifter, using either thermal, piezoelectric, mechanical or electrical means. Examples of phase shifter using a piezo bender and an actuator respectively are also disclosed. | 10-27-2011 |
| 20120044565 | DELAY LINE INTERFEROMETER WITH LIQUID CRYSTAL TUNING ELEMENT - A delay line interferometer is configured with a liquid-crystal (LC) tuning element as a phase modulator for demodulating a phase-modulated input signal. The LC tuning element allows for quickly tuning the phase difference between two optical signals separated from the phase-modulated input signal, so that the two optical signals can be coherently recombined to interfere with each other and produce one or more intensity-modulated optical signals. In some embodiments, the LC tuning element is configured to reduce polarization-dependent frequency shift without the use of additional high-precision optical elements and/or coatings. | 02-23-2012 |
| 20120099183 | OPTICAL DEMODULATOR - The embodiments of the present invention provides an optical demodulator, which includes a first reflective mirror, a second reflective mirror, a third reflective mirror, and an optical splitter. The optical splitter is configured to: split input light for the first time; split for the second time a first path of light reflected back by the first reflective mirror, where two paths of light obtained by splitting the first path of light are emitted to the first reflective mirror and the third reflective mirror respectively, split for the second time a second path of light reflected back by the second reflective mirror, where two paths of light obtained by splitting the second path of light are emitted to the first reflective mirror and the third reflective mirror respectively. | 04-26-2012 |
| 20120154901 | PLC-TYPE DELAY DEMODULATION CIRCUIT - A PLC-type delay demodulation circuit includes a planar lightwave circuit that is provided on one PLC chip and demodulates a DQPSK signal. The planar lightwave circuit includes a Y-branch waveguide that branches a DQPSK-modulated optical signal into two optical signals and first and second MZIs that delay the branched optical signals by one bit. The length of a short arm waveguide of the first MZI is different from the length of a short arm waveguide of the second MZI, and the length of an optical path from the Y-branch waveguide to output ports of the first MZI through the short arm waveguide of the first MZI is equal to that of an optical path from the Y-branch waveguide to output ports of the second MZI through the short arm waveguide of the second MZI. | 06-21-2012 |
| 20120162746 | PLC-TYPE DELAY DEMODULATION CIRCUIT - The PLC-type delay demodulation circuit includes a planar lightwave circuit that is provided on one PLC chip and demodulates a DQPSK signal. The planar lightwave circuit includes a Y-branch waveguide that branches a DQPSK-modulated optical signal into two optical signals and first and second MZIs that delay the branched optical signals by one bit. A wave plate is provided in central portions of first and second arm waveguides of the first MZI and first and second arm waveguides of the second MZI in such a manner that the wave plate intersects all of the four arm waveguides, the four arm waveguides being close to one another in a portion where the wave plate is provided. | 06-28-2012 |
| 20120182601 | Demodulator Using MEMS Chip for Adjusting The Phase - The present patent application provides a demodulator using MEMS chip for adjusting the phase, which comprises a first interferometer. The difference of the first optical path and the second optical path is an integer multiple of the light speed. A MEMS chip is arranged in at least one optical path of the first interferometer, the MEMS chip is used to adjust the phase of the interference light. The present patent application using MEMS chip for adjusting the phase and phase difference, and also monitor the location of the output beam waveform of the first interferometer and the second interferometer to guide the MEMS chip adjusting the phase difference of the two optical paths. Therefore the adjusting of the phase is more precise by using MEMS chip. | 07-19-2012 |
| 20130010350 | PLC-TYPE DELAY DEMODULATION CIRCUIT AND PLC-TYPE OPTICAL INTERFEROMETER - Disclosed are a PLC-type delay demodulation circuit and a PLC-type optical interferometer capable of reducing the size of a PLC chip with respect to the arrangement of various kinds of light output waveguides. In a PLC-type delay demodulation circuit, arm waveguides of a first MZI and arm waveguides of a second MZI are formed so as to overlap each other in the same region of a planar lightwave circuit. The optical paths of the MZIs are arranged such that the propagation directions of two DQPSK signals branched by a Y-branch waveguide are opposite to each other. | 01-10-2013 |
| 20130044366 | METHOD AND APPARATUS FOR CONTROLLING BIAS POINT OF DIFFERENTIAL QUADRATURE PHASE SHIFT KEYING DEMODULATOR - Method and apparatus for controlling bias point of DQPSK demodulator are disclosed. The method comprises: step | 02-21-2013 |
| 20130063806 | OPTICAL ANALOG-TO-DIGITAL CONVERTER, METHOD OF CONSTRUCTING THE SAME, OPTICAL SIGNAL DEMODULATOR, AND OPTICAL MODULATOR-DEMODULATOR - An optical A/D converter according to the present invention includes an optical splitter that splits an analog input signal light into plurals, a plurality of Mach-Zehnder interferometers to which each of the signal lights split by the optical splitter is input, and plurality of optical/electrical conversion unit that convert each signal lights output from each Mach-Zehnder interferometer into a digital electrical signal, in which each Mach-Zehnder interferometer includes optical intensity-to-phase conversion unit that optically convert intensity of the input signal light into an amount of phase shift and the amount of phase shift differs for each Mach-Zehnder interferometer. Then, it is possible to provide a high speed and low power consuming optical demodulation circuit. | 03-14-2013 |
| 20130208348 | PLC-TYPE DELAY DEMODULATION CIRCUIT - A PLC-type delay demodulation circuit includes a planar lightwave circuit that is provided on one PLC chip and demodulates a DQPSK signal. The planar lightwave circuit includes a Y-branch waveguide that branches a DQPSK-modulated optical signal into two optical signals and first and second MZIs that delay the branched optical signals by one bit. The length of a short arm waveguide of the first MZI is different from the length of a short arm waveguide of the second MZI, and the length of an optical path from the Y-branch waveguide to output ports of the first MZI through the short arm waveguide of the first MZI is equal to that of an optical path from the Y-branch waveguide to output ports of the second MZI through the short arm waveguide of the second MZI. | 08-15-2013 |
| 20130271822 | ATHERMAL DQPSK AND/OR DPSK DEMODULATOR - In some example embodiments, a demodulator may include an input polarization beam splitter (IPBS), input half waveplate (IHWP), cubical polarization beam splitter (CPBS), first reflector (R | 10-17-2013 |
| 20130271823 | MODULATED SIGNAL DETECTING APPARATUS AND MODULATED SIGNAL DETECTING METHOD - A phase difference error detecting unit detects a phase difference error component included in a phase difference component; a phase difference correcting unit corrects a first signal having the phase difference component as an angle of a cosine function and a second signal whose angle of the cosine function differs from that of the first signal by approximately π/2 based on the detected phase difference error component; a phase operating unit operates a phase difference component from the first signal and the second signal corrected by the phase difference correcting unit; and the phase difference correcting unit obtains the corrected first signal and the corrected second signal by rotating a coordinate point represented by the first signal and the second signal on a polar coordinate plane by an angle corresponding to the phase difference error component. | 10-17-2013 |
| 20140133012 | DP-QPSK DEMODULATOR - In an embodiment, a demodulator includes first, second, third, fourth and fifth beam displacers, a half waveplate, and a quarter waveplate. The second beam displacer is positioned to receive an output from the first beam displacer. The third beam displacer is positioned to receive an output from the second beam displacer. The half waveplate is positioned to receive an output from the third beam displacer. The fourth beam displacer is positioned to receive an output from the half waveplate. The fifth beam displacer is positioned to receive an output from the fourth beam displacer. The quarter waveplate is positioned between the fourth beam displacer and the fifth beam displacer. | 05-15-2014 |
| 20150355523 | SIGNAL PROCESSING METHOD OF MULTIPLE MIRCO-ELECTRO-MECHANICAL SYSTEM (MEMS) DEVICES AND COMBO MEMS DEVICE APPLYING THE METHOD - This invention provides a signal processing method of multiple micro-electro-mechanical system devices. The signal processing method includes: providing at least two MEMS devices; applying driving or modulating signals of different frequencies to the MEMS devices such that the MEMS devices generate respective MEMS signals with respective frequencies; and combining the MEMS signals with respective frequencies into one or more multi-frequency signals and outputting the multi-frequency signals, wherein a number of the multi-frequency signals is less than a number of the MEMS signals with respective frequencies. This invention also provides a combo MEMS device integrating two or more MEMS devices and two or more vibration sources. | 12-10-2015 |
