Patent application number | Description | Published |
20090135857 | FREQUENCY-TUNABLE TERAHERTZ LIGHT SOURCE DEVICE - Provided is a frequency-tunable terahertz light source device. The frequency-tunable terahertz light source device satisfies a Littrow diffraction condition at a wavelength and simultaneously satisfies a Littman-Metcalf diffraction condition at another wavelength using a double diffraction grating having two grating periods. Thus, oscillations simultaneously occur at the two different wavelengths, such that a terahertz wave can be stably generated by beating of the two oscillation wavelengths. In addition, the frequency-tunable terahertz light source device can readily change a frequency up to several terahertz and can be fabricated in a small size. | 05-28-2009 |
20090154505 | WAVELENGTH TUNABLE LASER DIODE USING DOUBLE COUPLED RING RESONATOR - A wavelength tunable laser diode using a double coupled ring resonator is provided. A new double coupled ring resonator structure is formed by a connection of two ring resonators having different radii so that stable laser oscillation occurs only in a resonant wavelength at which the two ring resonators are simultaneously resonated, and the effective refractive index of the two ring resonators is properly controlled differently for tunable laser oscillation wavelengths. The reproducibility of the optical coupling characteristics of the passive waveguides and the ring resonator can be assured by multi-mode couplers. This results in improved manufacturing productivity of the wavelength tunable laser diode. It is possible to amplify and output an output light without having an effect on oscillation wavelength characteristic by means of an optical amplifier integrated in an output end. | 06-18-2009 |
20090154923 | WAVELENGTH SELECTIVE SWITCH - Provided is a wavelength selective switch (WSS), and more particularly, a wavelength selective switch for electrically switching a wavelength without physical displacement. The wavelength selective switch includes an optical demultiplexer for dividing an input optical signal into signals having wavelengths corresponding to respective channels, selecting either the optical signal of each channel obtained by dividing the input optical signal or an optical signal input via an add port, and outputting the selected optical signal; and an optical multiplexer including an optical deflecting unit for individually deflecting the optical signals of the respective channels received from the optical demultiplexer according to supplied current or applied voltage, wherein the optical signal of each channel deflected by the optical deflecting unit is output to a specific output port. In the wavelength selective switch, current is supplied to the optical deflectors to switch the channels, resulting in higher reliability, smaller volume and higher switching speed than a conventional wavelength selective switch using mechanical displacement to switch channels. | 06-18-2009 |
20100142889 | WAVELENGTH TUNABLE OPTICAL INTERLEAVER - An optical interleaver of a wavelength division multiplexing (WDM) system includes an optical coupler, first and second waveguides, a high reflection mirror, and first and second phase shifters. The coupler divides an input optical signal. The first waveguide branches off from the coupler in a first direction. The second waveguide branches off from the coupler in a second direction for providing an optical path different from that provided by the first waveguide. The high reflection mirror is disposed at an end of the first waveguide for reflecting a first optical signal incident onto the first waveguide. The first phase shifter is disposed at an end of the second waveguide for multiple-reflecting a second optical signal incident onto the second waveguide. The second phase shifter is disposed at the first or second waveguide for adjusting an optical path difference between the first and second waveguides by varying its refractive index. | 06-10-2010 |
20100158524 | UPSTREAM SOURCE LIGHT GENERATOR OF PASSIVE OPTICAL NETWORK SYSTEM AND METHOD OF GENERATING UPSTREAM SOURCE LIGHT - Provided is an upstream source light generator of a passive optical network (PON) system. The upstream source light generator includes an amplification part configured to amplify injection light, and a reflection part configured to receive the amplified injection light and generate reflection light by reflecting the amplified injection light with different optical delays according to wavelengths of the amplified injection light. | 06-24-2010 |
20110002583 | OPTICAL DEVICE - Provided is an optical device. The optical device includes a multiplexer/demultiplexer, a multimode interference (MMI) coupler, a first waveguide, and second waveguides. The multiplexer/demultiplexer splits optical signals having a plurality of channels and received through a first port according to their wavelength to provide the split optical signals to second ports, or providing input optical signals having wavelengths difference from each other and received through the second ports to the first port. The multimode interference (MMI) coupler is connected to the first port. The first waveguide is connected to the MMI coupler. The second waveguides are connected to the second ports. The MMI coupler has a width decreasing toward the multiplexer/demultiplexer. | 01-06-2011 |
20110064422 | POLARIZATION SPLITTER, OPTICAL HYBRID AND OPTICAL RECEIVER INCLUDING THE SAME - Provided is an optical receiver used for an optical communication system, more particularly, a polarization split-phase shift demodulation coherent optical receiver. An optical hybrid includes a first optical splitter, a phase shift waveguide, a second optical splitter, and an optical coupler. The first optical splitter splits a first input optical signal to output first output optical signals. The phase shift waveguide receives the first output optical signals and controls and outputs the first output optical signals such that the first output optical signals have different phases. The second optical splitter splits a second input optical signal to output a plurality of second output optical signals. The optical coupler couples the first output optical signals one-to-one with the second output optical signals, respectively. | 03-17-2011 |
20110096855 | POLARIZATION DIVISION MULTIPLEXED OPTICAL ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING TRANSMITTER AND RECEIVER - Provided is a polarization division multiplexed optical OFDM transmitter. The polarization division multiplexed optical OFDM transmitter includes a data demultiplexer, a training symbol generation unit and an optical up-converter and polarization division multiplexing unit. The data demultiplexer divides a transmission signal into a plurality of groups. The training symbol generation unit allocates a plurality of training symbols for each OFDM data which is included in the respective multiplexed groups, and allocates repetitive data in a time domain for the respective training symbols for data of 0 to periodically appear for the respective training symbols in a frequency domain. The optical up-converter and polarization division multiplexing unit performs optical frequency band conversion and polarization division multiplexing on an output of the training symbol generation unit to output a polarization division multiplexed optical OFDM signal corresponding to a plurality of polarization components. | 04-28-2011 |
20110135319 | OPTICAL ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING RECEIVER AND OPTICAL SIGNAL RECEIVING METHOD THEREOF - Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme. | 06-09-2011 |
20110142398 | ADAPTER ASSEMBLY AND METHOD FOR COMPENSATING OPTICAL FIBERS FOR LENGTH DIFFERENCE - Provided are an adapter assembly and method for compensating optical fibers for a length difference. The adapter assembly includes a first adapter, a second adapter, and a member. The first adapter is configured to be connected to at least one optical communication unit. The second adapter is configured to be connected to at least another optical communication unit and be coupled to the first adapter. The member is configured to be interposed between the first and second adapters for providing an optical signal transmission path between the optical communication units. Owing to the member, a length difference between optical fibers can be compensated for. | 06-16-2011 |
20120114293 | OPTICAL WAVEGUIDE STRUCTURE HAVING ANGLED MIRROR AND LENS - The present disclosure relates to a planar optical waveguide element, and more particularly, to an optical waveguide end structure for effective optical signal connection with a light source, a light receiving element, or a different type of optical waveguide element. | 05-10-2012 |
20120132792 | OPTICAL MODULE COMPRISING OPTICAL HYBRID USING METAL OPTICAL WAVEGUIDE AND PHOTO DETECTOR - An exemplary embodiment of the present disclosure provides an optical module including: an optical hybrid including a metal optical waveguide; a photo detector configured to receive light; and a platform including an optical hybrid supporting section for supporting the optical hybrid, a photo detector supporting section for supporting the photo detector, and an inclined surface configured to change a propagation direction of light emitted from the optical hybrid, and configured to combine the optical hybrid and the photo detector. | 05-31-2012 |
20120155875 | OPTICAL RECEIVER - Disclosed is an optical receiver including: a polarization splitter splitting two polarization components perpendicular to each other from an optical signal to output a first polarization signal and a second polarization signal; a first optical delay splitter and a second optical delay splitter branching each polarization signal to output two branch signals, respectively; a first optical hybrid and a second optical hybrid each outputting four interference signals in which a phase shift increases by each 90° by using the two branch signals; and four photo detectors each outputting a differential signal between two interference signals in which the phase shift is 180° . | 06-21-2012 |
20120155887 | METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING COHERENT OPTICAL OFDM - Disclosed are a method and an apparatus for transmitting and receiving coherent optical OFDM. The apparatus includes: a transmitted OFDM digital signal processing unit outputting an in-phase (I) component digital signal and a quadrature phase (Q) component digital signal; a digital-analog converter converting the in-phase (I)-component digital signal and the quadrature-phase (Q)-component digital signal into an in-phase (I)-component analog signal and a quadrature-phase (Q)-component analog signal, respectively; an adder adding an additional pilot tone signal to each of the in-phase (I)-component analog signal and the quadrature-phase (Q)-component analog signal outputted from the digital-analog converter; and an optical I/Q modulator up-converting the in-phase (I)-component analog signal added with the additional pilot tone signal and the quadrature-phase (Q)-component analog signal added with the additional pilot tone signal to an optical domain to output a coherent optical OFDM signal including the additional pilot tone signal. | 06-21-2012 |
20130114956 | DPSK OPTICAL RECEIVER - Disclosed is a DPSK optical receiver capable of compensating for a polarization phase difference. The DPSK optical receiver according to an embodiment of the present disclosure includes: an optical splitter configured to split a received optical signal into a first optical signal and a second optical signal; an optical delay waveguide configured to delay the first optical signal; a birefringent waveguide configured to delay the second optical signal so as to compensate for a polarization phase difference at an output end; and an optical hybrid configured to generate an optical detection signal corresponding to a phase difference between the delayed first optical signal and the delayed second optical signal. | 05-09-2013 |
20130156362 | CORE AND OPTICAL WAVEGUIDE - Provided is a core which reduces optic splice loss between discontinuous optical waveguides. The core includes a first waveguide propagation portion having first light-receiving width, a first lightwave discontinuous portion having second light-receiving width, a first taper structure portion having both ends connected to the first lightwave propagation portion and to the first lightwave discontinuous portion, respectively and decreasing in light-receiving width as it goes from the first lightwave propagation portion to the first lightwave discontinuous portion, a second lightwave propagation portion having third light-receiving width, a second lightwave discontinuous portion having fourth light-receiving width, and a second taper structure portion having both ends connected to the second lightwave propagation portion and to the second lightwave discontinuous portion, respectively and decreasing in light-receiving width as it goes from the second lightwave propagation portion to the second lightwave discontinuous portion. | 06-20-2013 |
20130156394 | OPTICAL COMMUNICATION MODULE AND METHOD OF MANUFACTURING THE SAME - The inventive concept relates to an optical communication module. The optical communication module may include a metal block: an electrical device formed on the metal block; an optical device adhesive block formed on the metal block; an optical device formed on the optical device adhesive block and connected to the electrical device through a bonding interconnection; and a flat type optical waveguide formed on one side of the optical device adhesive block and optically aligned with the optical device. | 06-20-2013 |
20130156424 | APPARATUS FOR MEASURING PERFORMANCE OF COHERENT OPTICAL RECEIVER - An apparatus for measuring performance of a coherent optical receiver includes a beam splitter splitting light into first and second paths, a first optical modulator modulating the first path light, a variable optical attenuator controlling an optical power of the first optical modulator, a first polarization controller transmitting a signal controlling polarization of an output of the variable optical attenuator to the coherent optical receiver, a second optical modulator modulating the second path light, a variable optical delay line delaying time of an output of the second optical modulator, a second polarization controller transmitting a signal controlling polarization of an output of the variable optical delay line to the coherent optical receiver, a network analyzer measuring performance of the coherent optical receiver and controlling the optical modulators, and a controller transmitting a control signal to the optical modulators. | 06-20-2013 |
20130308949 | OPTICAL ORTHOGONAL FREQUENCY DIVISION MULTIPLE MULTIPLEXING RECEIVER AND OPTICAL SIGNAL RECEIVING METHOD THEREOF - Provided is an optical OFDM receiver. The optical OFDM receiver receives an optical signal dependent on the nonlinearity of a transmitter. The optical OFDM receives includes an optical down converter, a nonlinearity compensator, and an OFDM demodulator. The optical down converter converts the optical signal into an electrical signal. The nonlinearity compensator filters the electrical signal, for compensating distortion which is added to the optical signal when the transmitter performs optical modulation. The OFDM demodulator demodulates the distortion-compensated electrical signal in an OFDM scheme. | 11-21-2013 |
20140147131 | MULTI-CHANNEL PHOTORECEIVER MODULE - Provide an optical receiver module. The optical receiver module includes: an optical fiber array including a first optical fiber that delivers an optical signal and a second optical fiber that delivers a reference optical signal; a plate optical integrated circuit including first and second multi mode interference (MMI) optical isolators respectively receiving the optical signal and the reference optical signal through a plurality of first optical waveguides; and an optical detector array receiving two optical signals from each of the first and second MMI optical isolators through a plurality of second optical waveguides, wherein the optical detector array includes a plurality of third optical waveguides aligned to be connected to the other end of each of the plurality of second optical waveguides in one-to-one correspondence. | 05-29-2014 |
20140169786 | APPARATUS AND METHOD FOR MEASURING IQ IMBALANCE FOR OPTICAL RECEIVER - Provided is an apparatus and method for measuring IQ imbalance, and in particular, is an apparatus and method for measuring IQ imbalance for an optical receiver. The apparatus for measuring IQ imbalance for an optical receiver includes a light generating unit generating optical and reference signals to provide the optical and reference signals to an optical receiver, a graph creating unit creating a Lissajous figure by using an in-phase (I) signal and a quadrature-phase (Q) signal output from the optical receiver in response to the optical and reference signals, and a calculating unit calculating IQ imbalance for the optical receiver with reference to the Lissajous figure. | 06-19-2014 |
20140205280 | MEASURING DEVICE AND METHOD OF MEASURING SIGNAL TRANSMISSION TIME DIFFERENCE THEREOF - Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measureable range. | 07-24-2014 |