Patent application number | Description | Published |
20080219675 | APPARATUS AND METHOD FOR LIGHT INTENSITY MODULATION AND OPTICAL TRANSMISSION SYSTEM EMPLOYING THE SAME - A multilevel light intensity modulation system can generate a multilevel modulated optical signal from a single light source without handling multilevel electrical signals. The light from a light source | 09-11-2008 |
20080240736 | Inter-Symbol Interference-Suppressed Colorless DPSK Demodulation - An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer. | 10-02-2008 |
20090092393 | Coherent Optical Orthogonal Frequency Division Multiplexing (OFDM) Reception Using Self Optical Carrier Extraction - A method includes producing interference between a received optical OFDM signal and an optical carrier extracted from the received optical OFDM signal to provide optical coherent detection of the received optical OFDM signal. Preferably, producing the interference includes optically splitting the received optical OFDM signal into a first part that is filtered to extract the carrier from the received optical OFDM signal and a second part similar to the received optical OFDM signal. | 04-09-2009 |
20090162066 | Intra-Channel Equalizing Optical Interleaver - An apparatus includes an interleaver configuration for at least one of combining or separating odd and even channel groups to achieve channel density doubling; and an optical equalizer for suppressing inter symbol interference within the channels to provide intra-channel equalizing in the optical path, the equalizer being integrated into the interleaver. Preferably, optical equalizer and interleaver are integrated together as a single monolithic device, the optical equalizer includes a passband that has a dip in the channel center to achieve a raised-cosine filtering profile in the optical signal path to achieve inter-symbol interference ISI suppression, and the equalizer includes integration into the optical path of the interleaver to realize a monolithic device combining or separating odd and even channel groups to achieve channel density doubling. Preferably, also, the optical equalizer includes a first equalizer with half the depth of required ripple dips at both a first output port and an input port and a second equalizer with half the depth of required ripple dips at a second output port. | 06-25-2009 |
20100027994 | Phase Modulation Of An Optical Orthogonal Frequency Division Multiplexing Signal - A method includes generating an optical orthogonal frequency division multiplexing OFDM signal with in-phase and quadrature-phase components; varying an RF carrier according to the in-phase and quadrature-phase components; and modulating a phase of a lightwave carrier according to the varied RF carrier to generate an optical OFDM signal with equalized amplitude. | 02-04-2010 |
20100028001 | Generation Of At Least 100 Gbit/s Optical Transmission - A method includes generating at least two lightwave carriers from a lightwave source, the carriers having a wavelength spacing, creating an up-subchannel and a down-subchannel orthogonal to one another and spaced apart based on the fixed wavelength spacing from modulations of the lightwave carriers according to respective up-converted OFDM signals that are carrier suppressed, and combining one lightwave from the up-subchannel and one lightwave from the down-subchannel into an optical channel for transmission over an optical fiber. | 02-04-2010 |
20100226810 | Process for Manufacturing Metal Particles - Metal particles approximately in the form of spheres having a mean diameter of about 40 μm to about 100 μm, including magnesium silicide particles having a mean diameter of about 1 μm to about 10 μm uniformly dispersed in the metal particles, the metal particles being obtained by mixing about 90 wt. % to about 95 wt. % of magnesium and about 5 wt. % to about 10 wt. % of silicon, and the magnesium silicide particles being formed in the metal particles by the reaction of the magnesium and the silicon. | 09-09-2010 |
20100232789 | Modified Michelson Interferometer Structure for Inter-Symbol Interference-Suppressed Colorless DPSK Demodulation - An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer. | 09-16-2010 |
20100232803 | Integrated Equalizer and Michelson Interferometer Structure for Inter-Symbol Interference-Suppressed colorless DPSK demodulation - An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer. | 09-16-2010 |
20110075242 | OPTICAL SIGNAL GENERATION WITH D/A CONVERTERS AND OPTICAL CLOCK PULSE STREAM - An apparatus includes an optical train pulse generator for generating continuous optical pulses each having a narrow width; a clock source having a high frequency for triggering the generator and operable as a sampling clock; a digital-to-analog converter DAC for converting an input signal from a digital signal processor, the DAC responsive to the sampling clock; a data modulator responsive to an amplified output from the DAC to modulate the continuous optical pulses from the train pulse generator; and a filter for removing higher frequency harmonics from the modulated continuous optical pulses out of the data modulator. | 03-31-2011 |
20110176801 | TRANSMISSION UNIT, OPTICAL TRANSMISSION APPARATUS, COMMUNICATION CONTROL METHOD AND PROGRAM STORAGE MEDIUM - A transmission unit of this application includes a transmission unit, operating in one of modes including a normal communication mode and a connection confirmation mode, wherein the transmission unit transmits, in the normal communication mode, an OSC (Optical Supervisory Channel) signal with time average power beyond predetermined upper limit power; and wherein the transmission unit transmits, in the connection confirmation mode, the OSC signal with time average power lower than the upper limit power and with a transmission rate lower than a transmission rate in the normal communication mode. | 07-21-2011 |
20120224848 | OPTICAL FIBER TRANSMISSION SYSTEM AND POWER CONTROL METHOD OF THE SAME - An optical transmission system includes a first node and a second node, the first node includes a first optical amplifier which outputs a signal to the second node through a first transmission line and a first monitoring unit, the second node includes a monitor which monitors a signal from the first transmission line, a second optical amplifier which outputs a signal to the first node through a second transmission line and a second monitoring unit, upon detecting disconnection from the first transmission line, the second monitoring unit transmits a notification for making power of the first optical amplifier reduced, upon receipt of the notification, the first monitoring unit reduces power of the first optical amplifier, and transmits a completion notification to the second monitoring unit, and upon not receiving the completion notification even after expiration of an allowed time, the second monitoring unit reduces power of the second optical amplifier. | 09-06-2012 |
20130051796 | TRANSPONDER DEVICE, OPTICAL BRANCHING DEVICE, AND OPTICAL SIGNAL TRANSMISSION METHOD IN OPTICAL TRANSPORT NETWORK NODE - A transponder device that can form D&C paths with great versatility and high reliability without complicating a device configuration is provided, as well as an optical branching device and an optical signal transmission method. The transponder device that is independent of any directions of a wavelength switching function section at a node in a WDM transport network includes a D&C branching means that branches an optical signal input from the wavelength switching function section into one stream of dropped light and at least one stream of continued light. | 02-28-2013 |
20140198853 | FADE TYPE DETERMINATION DEVICE - A fade state determination unit ( | 07-17-2014 |