Abstract: An active alignment method for a multi-channel optical transmitter and receiver is disclosed. The active alignment method for a multi-channel optical transmitter includes actively aligning an optical signal generator with an optical multiplexer based on optical outputs of a plurality of wavelengths from the optical signal generator and an optical output of the optical multiplexer, and actively aligning the optical multiplexer with a fiber optic coupler based on an optical output of the optical multiplexer and an optical output of the fiber optic coupler.

Abstract: Disclosed is an optical transceiver module for controlling power in each lane. The optical transceiver module includes: a plurality of transmitting units formed in each lane in order to transmit signals to receive electric signals in each lane, convert the received electric signals into optical signals, and transmit the converted optical signals, respectively; a first switching means turning on/off power supplied to each of the plurality of transmitting units in each lane; a plurality of receiving units formed in each lane to receive optical signals in each lane, convert the received optical signals into electric signals, and output the converted electric signals, respectively; a second switching means turning on/off power supplied to each of the plurality of receiving units in each lane; and a control means controlling switching operations of the first switching means and the second switching means.

Abstract: There is provided an optical module having a top open can (TO-CAN) structure. The optical module having the TO-CAN structure includes a stem that accommodates an optical element or an electronic element therein, and a lead pin that is connected to the optical element or the electronic element through a hole of the stem, wherein the lead pin is bent in a “” shaped structure. Accordingly, the optical module with the TO-CAN structure may operate at high speed and be manufactured at low cost.

Abstract: Disclosed is a structure for impedance matching by applying a CPW structure to an impedance discontinuous portion on a data signal line or using a micro-strip open stub so as to be used for high-speed transmission by a flexible PCB. According to the present invention, it is possible to fabricate a flexible PCB capable of performing low-priced and high-speed transmission.

Abstract: An optical module includes a stem, an optical element, data signal lead pins, a printed circuit board, and a post portion. The optical element is mounted on one surface of the stem. The data signal lead pins are connected to the optical element, and protrudes through the other surface of the stem. The printed circuit board has one surface on which data signal transmission lines for contact with the data signal lead pins are formed and the other surface on a part of which a stiffener is formed to protrude. The post portion protrudes from the other surface of the stem, supports the printed circuit board while in close contact with the stiffener such that the data signal lead pins can contact the data signal transmission lines while being disposed linearly above the data signal transmission lines, and includes a coupling portion to be coupled with the stiffener.

Abstract: An optical transceiver which can effectively reduce optical output jitter when an error is made during designing and manufacturing of a printed circuit board (PCB), and a method of controlling optical output jitter using the optical transceiver are provided. The optical transceiver includes a transmitter unit including an equalizing (EQ) filter which can reduce jitter of a high speed electric signal; a control circuit which controls the EQ filter; a receiver unit which receives an optical signal; and a micro-controller which controls the transmitter unit and the receiver unit.

Abstract: Provided are a multiplexing and demultiplexing apparatus and method of a multi-wavelength optical signal that may dispose each of thin film filters in a location where a zigzag reflection occurs in a zigzag optical path, and thereby multiplex or demultiplex a multi-wavelength optical signal using the thin film filters. Each of the thin film filters may transmit an optical signal having a predetermined wavelength which is incident at a predetermined incidence angle, and reflect a remaining wavelength optical signal at a predetermined reflection angle.

Abstract: An optical transceiver includes: a transmission unit configured to convert a first electrical signal into a first optical signal and transmit the converted first optical signal; a first power supply unit configured to supply power to the transmission unit; and a controller configured to control the first power supply unit, wherein the controller controls an operation of the first power supply unit according to whether or not the first electrical signal is inputted to the transmission unit.

Abstract: A multi-wavelength optical transmitting module includes a housing, an optical output block, an optical transmitting block, and an optical multiplexer (MUX) block. The housing has a first coupling hole and a second coupling hole respectively formed in opposite surfaces thereof. The optical output block is coupled to the first coupling hole of the housing, is connected to an optical signal connector, and includes a first lens. The optical transmitting block is coupled to the second coupling hole of the housing and is connected to an electrical signal connector. In addition, the optical transmitting block includes a plurality of transmitting devices which respectively output light having different wavelengths and are arranged parallel to the optical output block, and a plurality of second lenses which are arranged on a light output side of the transmitting devices to correspond respectively to the transmitting devices.

Abstract: A wavelength-division apparatus and a wavelength combining apparatus are provided. Each of the wavelength-division apparatus and the wavelength combining apparatus includes a transparent block having one surface which is coated with an anti-reflective coating layer and the other surface which is coated with a partial transmitting coating layer. Each of the anti-reflective coating layer and the partial transmitting coating layer is coupled to a plurality of wavelength-selective filters that separate optical signals of different wavelengths through different paths other than a transmission path or a receiving path. Thus, the optical signals of the respective wavelengths output through the different paths can be used for various purposes such as monitoring the signal intensity and/or the signal quality.

Abstract: Provided are an apparatus and method for maintaining an constant extinction ratio of a laser diode (LD). The apparatus includes: an automatic power control circuit maintaining the constant optical power of the LD; a correlation deriver deriving correlations between a bias current of the LD and a modulation current to maintain the constant extinction ratio of the LD; and a modulation current control circuit controlling the modulation current to maintain constant the extinction ratio of the LD based on the correlations. The apparatus and method do not use a temperature sensor but derive a relationship between variances of a bias current of the LD and a modulation current according to temperature change, control the modulation current based on the relationship, and maintain the constant extinction ratio of the LD.

Abstract: An active alignment method for a multi-channel optical transmitter and receiver is disclosed. The active alignment method for a multi-channel optical transmitter includes actively aligning an optical signal generator with an optical multiplexer based on optical outputs of a plurality of wavelengths from the optical signal generator and an optical output of the optical multiplexer, and actively aligning the optical multiplexer with a fiber optic coupler based on an optical output of the optical multiplexer and an optical output of the fiber optic coupler.

Abstract: An optical transmitter is provided which optimizes DC bias voltage input to an optical modulator employing a duo-binary modulation scheme. The optical transmitter including a signal combiner which converts an electrical signal for optical transmission into a high-speed electrical signal, and an optical modulator which receives and modulates the high-speed electrical signal from the signal combiner further includes a frequency divider to divide frequency of a sinusoidal watchdog clock signal from the signal combiner and to output the divided signal to be added to direct current (DC) bias voltage input to the optical modulator; and a bias voltage modifier to adjust the DC bias voltage by analyzing the modulated electrical signal from the optical modulator. Accordingly, it is possible to conveniently optimize the DC bias voltage with a simple design.

Abstract: An optical transceiver for optimizing transfer characteristic of an optical interferometer and a method of optimizing transfer characteristic of an optical interferometer of an optical transceiver are provided. It is possible to improve the transmission performance of the optical transceiver by optimizing the transfer characteristic of the optical interferometer included in an optical receiver of the optical transceiver which transmits and receives an optical signal in a phase modulation scheme.

Abstract: Provided is an optical transponder that receives a tributary signal such as a SDH/SONET signal, a GbE (Gigibit Ethernet) signal, and a SAN (Storage Area Network) signal in a WDM (Wavelength Division Multiplexing) transmission system and a SDH (Synchronous Digital Hierarchy)/SONET (Synchronous Optical Network) system, and more particularly, to an optical transponder having a switching function. The optical transponder having a switching function includes: a switch changing a data path of an input tributary signal from a plurality of channels (ports); an STM-64/OC-192 mapper/demapper mapping the tributary signal switched to a different data path by the switch to an STM-64/OC-192 signal or demapping the STM-64/OC-192 signal to the tributary signal; and a transmission delay time compensator compensating for a differential delay caused by a transmission route difference on an optical fiber link when the STM-64/OC-192 signal is demapped to the tributary signal.

Abstract: Provided are an optical transponder that interfaces a multiprotocol signal and a method of interfacing a multiprotocol signal. The optical transponder includes: an optical transceiver, which optical/electrical converts and multiplexes/demultiplexes an input signal; a reception clock generator, which generates a clock on a reception path; a transmission clock generator, which generates a clock on a transmission path; an optical transport hierarchy (OTH) framer, which processes an OTH signal when the input signal is the OTH signal; a synchronous digital hierarchy (SDH)/synchronous optical network (SONET) framer, which processes an SDH/SONET signal or a gigabit Ethernet (GbE) when the input signal is the SDH/SONET signal or the GbE signal; and a controller which controls the optical transceiver, the reception clock generator, the transmission clock generator, the OTH framer, and the SDH/SONET framer according to the type of the input signal.

Abstract: Provided are an optical transponder that processes a G.709 frame that includes an overhead for operation, administration, and maintenance of an optical channel and an overhead for forward error correction, and a method of detecting and treating errors in optical-channel sublayers of the same. The method includes detecting an error signal or a maintenance signal from a G.709 frame that includes an overhead for operation, administration, and maintenance of an optical channel and an overhead for forward error correction; treating errors in a predetermined layer of a plurality of layers that requires error treatment when the error signal or the maintenance signal is detected or canceled; and investigating a reason for the errors in the predetermined layer.

Abstract: Provided is an apparatus for testing the performance of an optical transceiver by referencing various performance clocks provided by an OTU2 signal connection transceiver and an STM-64/OC-192 signal. The apparatus for testing performance of an optical transceiver includes: a transmitter/receiver reference clock selector for selecting one of various transmitter/receiver reference clocks provided by an STM-64/OC-192 connection optical transceiver or an OTN connection optical transceiver; a transmitter test reference clock selection switch for selecting a receiver data synchronous clock provided by the transceivers or the selected transmitter/receiver reference clock as a transmitter test reference clock; and a receiver test reference clock selection switch for selecting a transmitter supervisory clock provided by the transceivers or the selected transmitter/receiver reference clock as a receiver test reference clock.

Abstract: An optical transceiver which can effectively reduce optical output jitter when an error is made during designing and manufacturing of a printed circuit board (PCB), and a method of controlling optical output jitter using the optical transceiver are provided. The optical transceiver includes a transmitter unit including an equalizing (EQ) filter which can reduce jitter of a high speed electric signal; a control circuit which controls the EQ filter; a receiver unit which receives an optical signal; and a micro-controller which controls the transmitter unit and the receiver unit.

Abstract: Disclosed herein is an apparatus for controlling a decision threshold voltage to an optical receiver, which is capable of automatically controlling the decision threshold voltage to the optical receiver appropriately to signal level decision on the basis of a low-frequency band signal component of an output signal from the optical receiver. The apparatus is adapted to control the level of the decision threshold voltage to the optical receiver, which converts an input optical signal into an electrical signal.