Abstract: An optical transceiver and a method of setting a wavelength of the optical transceiver. The optical transceiver may include a thermoelectric cooler (TEC) configured to maintain a constant operating temperature of a transmitter optical sub-assembly (TOSA) of the optical transceiver based on an installation environment of the optical transceiver, a plurality of laser diodes arranged on the top of the TEC and configured to output optical signals having different wavelengths, an optical multiplexer configured to multiplex the optical signals having different wavelengths, output through the plurality of laser diodes, and a wavelength controller configured to control the wavelengths of the optical signals output through the plurality of laser diodes such that optical outputs of the optical signals having different wavelengths, detected through the optical multiplexer, are maximized, wherein the wavelength controller may be individually arranged in one region of each of the plurality of laser diodes.

Abstract: An optical signal transmission apparatus generates a multi-level optical signal from a multi-level electric signal. The optical signal transmission apparatus detects, based on a supervisory signal generated from an optical signal, an electric-to-optical (E/O) conversion characteristic of an E/O converter configured to convert an electric signal into an optical signal. For example, when the E/O converter generates a multi-level optical signal from a multi-level electric signal based on a bias signal, the optical signal transmission apparatus determines a correspondence relationship between the bias signal and the optical signal. The optical signal transmission apparatus adjusts a use range of intensities of the bias signal based on the determined correspondence relationship so that the E/O converter may linearly operate.

Abstract: An optical receiver includes: an optical demultiplexer to demultiplex an optical signal in which a plurality of wavelengths is multiplexed and divide the optical signal into optical signals corresponding to the plurality of wavelengths, respectively; a reflector to change a progress direction of the divided optical signals; an optical coupling lens including, in an array form, light transmission lenses through which the divided optical signals are transmitted, respectively; a plurality of photodetectors to mount on a photodiode (PD) substrate provided on the optical coupling lens, receive the divided optical signals that are transmitted through the light transmission lenses of the optical coupling lens, respectively, and convert the received optical signals to electrical signals; and a plurality of trans impedance amplifiers provided at desired intervals to electrically connect to the plurality of photodetectors through wire bonding and amplify the received plurality of electrical signals to be a desired magn

Abstract: Provided is a device and method for detecting an optical signal. The optical signal detecting device may include an optical de-multiplexer configured to de-multiplex an input optical signal to optical signals of different wavelengths; an optical coupling lens configured to allow the optical signals of different wavelengths to be incident; an optical signal reflector configured to reflect the optical signals of different wavelengths emitted from the optical couple lens; and an optical detector configured to detect the reflected optical signals of different wavelengths.

Abstract: An optical receiver and a method of controlling the optical receiver. The method may include setting, by a controller, a dispersion value of a dispersion compensator to compensate for a dispersion of an optical signal received through an optical fiber, compensating, by the dispersion compensator, for the dispersion of the optical signal based on the set dispersion value, performing, by the controller, an error correction with respect to the optical signal of which the dispersion is compensated and verifying a number of bit errors, and resetting, by the controller, the dispersion value of the dispersion compensator based on the verified number of bit errors.

Abstract: An optical signal transmission apparatus generates a multi-level optical signal from a multi-level electric signal. The optical signal transmission apparatus detects, based on a supervisory signal generated from an optical signal, an electric-to-optical (E/O) conversion characteristic of an E/O converter configured to convert an electric signal into an optical signal. For example, when the E/O converter generates a multi-level optical signal from a multi-level electric signal based on a bias signal, the optical signal transmission apparatus determines a correspondence relationship between the bias signal and the optical signal. The optical signal transmission apparatus adjusts a use range of intensities of the bias signal based on the determined correspondence relationship so that the E/O converter may linearly operate.

Abstract: An optical receiver includes: an optical demultiplexer to demultiplex an optical signal in which a plurality of wavelengths is multiplexed and divide the optical signal into optical signals corresponding to the plurality of wavelengths, respectively; a reflector to change a progress direction of the divided optical signals; an optical coupling lens including, in an array form, light transmission lenses through which the divided optical signals are transmitted, respectively; a plurality of photodetectors to mount on a photodiode (PD) substrate provided on the optical coupling lens, receive the divided optical signals that are transmitted through the light transmission lenses of the optical coupling lens, respectively, and convert the received optical signals to electrical signals; and a plurality of trans impedance amplifiers provided at desired intervals to electrically connect to the plurality of photodetectors through wire bonding and amplify the received plurality of electrical signals to be a desired magn

Abstract: An optical signal detecting apparatus and method. The optical signal detecting apparatus includes an optical demultiplexer configured to demultiplex an input optical signal into a first optical signal having a first band wavelength and a second optical signal having a second band wavelength, a first optical detector configured to detect the first optical signal, and a second optical detector configured to detect the second optical signal, and the optical demultiplexer, the first optical detector, and the second optical detector may be provided in a TO-CAN package.

Abstract: Provided is a device and method for detecting an optical signal. The optical signal detecting device may include an optical de-multiplexer configured to de-multiplex an input optical signal to optical signals of different wavelengths; an optical coupling lens configured to allow the optical signals of different wavelengths to be incident; an optical signal reflector configured to reflect the optical signals of different wavelengths emitted from the optical couple lens; and an optical detector configured to detect the reflected optical signals of different wavelengths.

Abstract: An optical signal detecting apparatus and method. The optical signal detecting apparatus includes an optical demultiplexer configured to demultiplex an input optical signal into a first optical signal having a first band wavelength and a second optical signal having a second band wavelength, a first optical detector configured to detect the first optical signal, and a second optical detector configured to detect the second optical signal, and the optical demultiplexer, the first optical detector, and the second optical detector may be provided in a TO-CAN package.

Abstract: An optical demultiplexing device includes a demultiplexer configured to demultiplex an input light into lights of different wavelength bands, and output the lights of different wavelength bands in a first direction and a second direction, and a detector configured to detect the light output in the first direction and the light output in the second direction.

Abstract: A receptacle-collimator assembly and a multi-wavelength optical receiver module. The receptacle-collimator assembly includes a receptacle configured to receive a wavelength-multiplexed optical signal; and a collimator integrated with the receptacle and configured to generate a collimated beam signal from a multi-wavelength optical signal received from the receptacle and output the beam signal.

Abstract: A light signal multiplexer and a light signal demultiplexer corresponding to the light signal multiplexer. The light signal multiplexer may include a reflector and a filter, in which the reflector is disposed on a plurality of input light paths to allow a plurality of light signals input along the input light paths to be reflected toward the filter disposed on at least one output light path, and the filter is disposed to allow the light signals reflected toward the filter to be reflected along the at least one output light path, and thus the light signal multiplexer may individually set the input light paths for the light signals.

Abstract: A wavelength-division multiplexing optical communication system and a method for measuring optical performance of an output signal for the system. The optical communication system includes: a service-provider device; a local node; and a plurality of subscriber devices. The service-provider device includes: a plurality of first optical transceivers; a first optical multiplexer/demultiplexer (OD/OM) connected to the plurality of first optical transceivers; and a seed-light source providing seed light. Each subscriber device includes a second optical transceiver. The local node connects the service-provider device and the plurality of subscriber devices to each other using aDWDM link comprising: a second multiplexer/demultiplexer (OD/OM); and a single-mode optical fiber for transmission. Here, the optical intensity of an output signal of the second optical transceiver is determined by compensating for the value of the loss caused when the output signal passes through the second OD/OM of the local node.

Abstract: A receptacle-collimator assembly and a multi-wavelength optical receiver module. The receptacle-collimator assembly includes a receptacle configured to receive a wavelength-multiplexed optical signal; and a collimator integrated with the receptacle and configured to generate a collimated beam signal from a multi-wavelength optical signal received from the receptacle and output the beam signal.

Abstract: A wavelength-division multiplexing optical communication system and a method for measuring optical performance of an output signal for the system. The optical communication system includes: a service-provider device; a local node; and a plurality of subscriber devices. The service-provider device includes: a plurality of first optical transceivers; a first optical multiplexer/demultiplexer (OD/OM) connected to the plurality of first optical transceivers; and a seed-light source providing seed light. Each subscriber device includes a second optical transceiver. The local node connects the service-provider device and the plurality of subscriber devices to each other using a DWDM link comprising: a second multiplexer/demultiplexer (OD/OM); and a single-mode optical fiber for transmission. Here, the optical intensity of an output signal of the second optical transceiver is determined by compensating for the value of the loss caused when the output signal passes through the second OD/OM of the local node.

Abstract: A controlling method for mitigating a rogue behavior of an Optical Network Unit (ONU) having a wavelength-tunable function in a hybrid Passive Optical Network (PON) system. The controlling method includes determining whether a first wavelength for an upstream signal received from the ONU strays away from an allowable range for a second wavelength assigned to the ONU, and, in response to a determination that the first wavelength strays away from the allowable range for the second wavelength, transmitting an upstream wavelength adjustment request message to the ONU to adjust a wavelength for the upstream signal. At this point, a determination on whether the first wavelength strays away from the allowable range for the second wavelength is made by calculating wavelength drift of the first wavelength and determining whether the calculated wavelength drift is greater than a drift threshold.

Abstract: A tunable optical network unit (ONU) for a multi-wavelength passive optical network (MW PON) system and an operation method thereof are provided. The tunable ONU includes a cyclic tunable filter configured to have cyclic wavelength transmission properties that allow all wavelength channels of both a downstream signal and an upstream signal and to vary a wavelength to pass therethrough; a wavelength splitter configured to split an upstream signal wavelength band and a downstream signal wavelength band; a photodetector element configured to detect a downstream signal that is transmitted through the wavelength splitter, passing through the cyclic tunable filter which is aligned to a specific downstream signal wavelength channel; and a tunable transmitter configured to output to the wavelength transmitter an upstream signal of a wavelength channel that is determined based on an aligned downstream signal wavelength channel of the cyclic tunable filter.

Abstract: Provided is a hybrid passive optical network (PON) system. The hybrid PON system of wavelength division multiplexing (WDM)/time division multiplexing (TDM) may include an optical line terminal (OLT) and an optical network unit (ONU). The OLT and the ONU may transmit a signal based on wavelength reuse using a seed light source and a reflective modulator. The light source may include a seed light source having a single wavelength, two seed light sources having different wavelength bands, and a light source having a wavelength tunable characteristic.

Abstract: A tunable optical network unit (ONU) for a multi-wavelength passive optical network (MW PON) system and an operation method thereof are provided. The tunable ONU includes a cyclic tunable filter configured to have cyclic wavelength transmission properties that allow all wavelength channels of both a downstream signal and an upstream signal and to vary a wavelength to pass therethrough; a wavelength splitter configured to split an upstream signal wavelength band and a downstream signal wavelength band; a photodetector element configured to detect a downstream signal that is transmitted through the wavelength splitter, passing through the cyclic tunable filter which is aligned to a specific downstream signal wavelength channel; and a tunable transmitter configured to output to the wavelength transmitter an upstream signal of a wavelength channel that is determined based on an aligned downstream signal wavelength channel of the cyclic tunable filter.