Abstract: In some embodiments, a plurality of smart flow cytometers are coupled into communication with a computer communication network. A central repair server system is coupled into communication with the computer communication network and the plurality of smart flow cytometers. Each of the plurality of smart flow cytometers includes a monitoring system coupled to monitor differing operational parameters of the smart flow cytometer for possible failure. The monitoring system can detect an advanced failure of components based on the operational parameters being monitored. The monitoring system can also detect an advanced need for repair and maintenance based on the operational parameters being monitored.

Abstract: A power supply device is such that when an output voltage is abnormal, a system manager or the like can easily acquire information effective in identifying a cause of the abnormality. The power supply device includes a first light emitting element installed to be visually recognizable from an exterior, and a light emitting element control unit that drives the first light emitting element. When an output voltage is abnormal, the light emitting element control unit causes the first light emitting element to flash, thereby convert at least one of specific power supply operation information used for inferring a cause of the output voltage being abnormal and cause information inferred based on the specific power supply operation information into an optical digital signal formatted for serial communication, and causes the optical digital signal to be output from the first light emitting element.

Abstract: In some embodiments, a smart flow cytometer includes a monitoring system to monitor differing operational parameters of the smart flow cytometer to detect an advanced failure of components and an advanced need for maintenance. In others, a smart flow cytometer includes a quality control system including a reservoir of quality control beads to periodically run a validation test with the quality control beads in order to determine the ability of the flow cytometer to generate quality data output from a plurality of light detectors. In some embodiments, a plurality of smart flow cytometers are coupled into communication with a computer communication network; a central repair server system is coupled into communication with the computer communication network and the plurality of smart flow cytometers; wherein each of the plurality of smart flow cytometers includes a monitoring system coupled to monitor differing operational parameters of the smart flow cytometer for possible failure.

Abstract: A hot-pluggable optical transceiver capable of being inserted into an apparatus is equipped with an optical reception circuit; an optical transmission circuit; a signal processing circuit; a nonvolatile memory; a control unit controlling each of the portions of the transceiver; an insertion detection terminal; a reset terminal; and an alarm terminal. When the insertion detection terminal has a voltage that is smaller than a predetermined value, the control unit is allowed to receive the reset signal from the apparatus through the reset terminal. When the insertion detection terminal has a voltage that is larger than the predetermined value, the control unit is allowed to load new software by receiving a clock signal from the apparatus through the reset terminal and receiving a data signal synchronized with the clock signal from the apparatus through the alarm terminal and to store the new software in the nonvolatile memory.

Abstract: There is provided an optical communication system comprising: a transmitter comprising: a modulator configured to output a digital signal representing information to be transmitted; a biaser configured to output a bias level; a drive level controller configured to output a control signal; a switch electrically connected to the modulator, wherein the switch receives the digital signal and a reference voltage set by the control signal; and at least one light emitting diode (LED) electrically connected to the switch and the biaser. The LED is configured to emit light and pulse at varying power levels between the bias level and the reference voltage. The system further comprises a receiver comprising: a detector configured to receive light emitted by the LED and output a detected signal; and a demodulator configured to receive the detected signal and output demodulated information.

Abstract: An apparatus for saving power in an field programmable gate array (FPGA) in an optical communication device is provided. The apparatus includes at least one ring oscillator having an operating frequency disposed inside the FPGA, a core voltage switching unit configured to supply a core operating voltage to the FPGA, and control logic configured to adaptively output an adjusted new core voltage to the FPGA via the core voltage switching unit. The control logic is configured to output a core voltage control signal to the core voltage switching unit based on the operating frequency of the at least one ring oscillator. The core voltage switching unit is further configured to supply the adjusted new core voltage to the FPGA in accordance with the core voltage control signal.

Abstract: A device comprises an interface, a transmitter, a receiver, a processor, and a dynamically updating indicator on the device. The interface is configured to connect to an optical network transceiver. The transmitter is configured to send to the optical network transceiver a binary signal generated by the device. The receiver is configured to receive data provided by the optical network transceiver in response to sending the generated binary signal. The processor is configured to analyze the received data and the dynamically updating indicator is configured to indicate a test status of the optical network transceiver.

Abstract: Methods according to the disclosure include methods for controlling an optical communications system. The method may include adjusting a VCSEL transmitter of the optical communications system to operate at a second data bandwidth distinct from its first data bandwidth; reducing a data flow rate of a receiver during operation of the optical communications system at the second data bandwidth; determining whether a system quality metric for the receiver meets a specification requirement; in response to determining the system quality metric does not meet the specification requirement, adjusting an operational setting of the VCSEL transmitter or the receiver; in response to determining the system quality metric meets the specification requirement, continuing operation of the optical communications system at the second data bandwidth; and in response to receiving an override signal, resuming operation of the optical communications system at the first data bandwidth.

Abstract: A first optical transceiver node comprises: a laser configured to emit an input optical signal; a first splitter coupled to the laser and configured to split the input optical signal into a local oscillator (LO) optical signal and an unmodulated optical signal; and a receiver coupled to the first splitter and configured to: receive the LO optical signal from the first splitter; receive a modulated optical signal from a second optical transceiver node, wherein the modulated optical signal is a modulated version of the unmodulated optical signal; and perform phase noise cancellation of the modulated optical signal using the LO optical signal.

Abstract: A method for transmitting a coherent optical data signal includes receiving a data signal from an interface, and encoding the data signal with a forward error correcting (FEC) encoder according to a mix of modulation formats. The FEC encoder generates an FEC encoded signal which is used to generate modulation symbols according to the modulation formats. The FEC encoded signal of modulation symbols is spectrally shaped to generate a shaped signal, and pre-distorted before transmission. The shaped signal is pre-distorted by adding a predetermined amount of chromatic dispersion to generate a smoothed signal, and the smoothed signal is transmitted according to the modulation formats.

Abstract: An optical transceiver performs dual mode operations in an optical network. The dual mode operations include a single-fiber mode, in which a single fiber connecting the optical transceiver and another network node carries bi-directional optical signals, and a dual-fiber mode, in which two fibers connecting the optical transceiver and another network node carry respective uni-directional optical signals in opposite directions. A switching module coupled to the optical transceiver is set in accordance with a control signal such that a transmitter module transmits and a receiver module receives via a first optical connector receptacle to enable the single-fiber mode, or such that the transmitter module transmits via the first optical connector receptacle and the receiver module receives via a second optical connector receptacle to enable the dual-fiber mode.

Abstract: A household appliance includes an information light device that projects light onto a surface to enable a user to determine whether or not the household device is in operation. The information light device may include a light guide. The light guide may be disposed along a side portion of the household appliance.

Abstract: A method by an optical network unit ONU includes, for downstream transmission, using a first tunable laser for coherent detection on a sub-band basis to increase receiver sensitivity and reduce analog-to-digital conversion ADC and digital signal processor DSP requirements within the ONU, and for upstream transmission, using a second tunable laser and using an optical signal beating between the first and second tunable lasers to generate a tunable radio frequency RF signal source for upstream multi-band OFDMA signal generation thereby avoiding need for an otherwise more costly RF clock source within the ONU, enabling low-speed digital-to-analog conversion DAC operation and rendering the ONU colorless in both optical and radio frequency RF domains.

Abstract: An optical access network with centralized digital optical line termination OLT including an optical line termination unit having a digital transmitter and a coherent receiver for downstream signal transmitting and upstream signal receiving, and at least one optical network unit ONU with transceiver functions for communicating with the OLT over an optical path, the ONU including intensity modulation and single photodiode detection, wherein the digital transmitter includes digital signal processing DSP, digital-to-analog conversion DAC and analog-to-digital conversion ADC functions that can be shared by all multiple ones of the ONU in the network, the DSP reducing or removing dispersion and non-linearity effects in the network and the coherent receiver enabling performance of the downstream stream signal transmitting to match that of the upstream signal receiving in the OLT.

Abstract: The invention is directed to apparatus, systems and methods enabling a service provider to establish an optical demarcation point located at or within equipment controlled at least in part by a customer's domain such that the service provider's domain is able to directly control access of an optical signal to their domain.

Abstract: Methods, algorithms, architectures, circuits, and/or systems for determining the status of parameters associated with optical transceiver operation are disclosed. The method can include (a) accessing and/or monitoring parametric data for each of a plurality of parameters that are related to operation of the optical transceiver; (b) storing the parametric data in one or more memories; (c) comparing the parametric data for each of the plurality of parameters against at least one of a corresponding plurality of predetermined thresholds; and (d) generating one or more states indicating whether the parametric data for a unique one of the parameters has crossed one or more of the corresponding plurality of predetermined thresholds. The invention also relates to an optical triplexer, comprising the described optical transceiver.

Abstract: An apparatus in one embodiment includes a transceiver housing operable to be inserted into a port of a host system, the port comprising at least a first channel and a second channel. The transceiver housing may be a compact small form-factor (SFP) pluggable module housing. The apparatus also includes a printed circuit board mounted in the transceiver housing and an electrical interface of the printed circuit board operable to interface with the port of the host system. The electrical interface includes a first transmit pin and a first receive pin configured to interface with the first channel of the port and a second transmit pin and a second receive pin configured to interface with the second channel of the port. A first connector couples the first transmit pin and the second receive pin, and a second connector couples the second transmit pin and the first receive pin.

Abstract: An optical system has an optical emitter that transmits an optical signal through an optical fiber. An optical detector detects light from the fiber and provides an analog signal indicative of such light. A crosstalk cancellation element is configured to receive an electrical signal from the optical emitter and to adjust such signal in order to form a cancellation signal that models the optical and/or electrical crosstalk affecting the analog signal. The cancellation signal is subtracted from the analog signal thereby removing optical and/or electrical crosstalk from the analog signal.

Abstract: A system includes two optical modules that perform auto-setting of the optical links between the optical modules. One optical module sends an optical signal with a test pattern to the other optical module. If the receiving module determines that the test pattern is successfully received, it sends a pass indication to the transmitting module, and the transmitting module can configure its driver path in accordance with a transmit current setting used to transmit the test pattern. If the test pattern is not successfully received, the receiving module sends a fail indication, and the transmitting module can increase the transmit current setting and resend the test pattern. When the system includes multiple optical channels, one channel can be tested while feedback is provided on another channel. The system can iterate through all optical channels until they are all configured.

Abstract: The object of the present invention is to reliably prevent deterioration and failure of reception relevant parts in a transmission apparatus on a reception side without using an attenuator. An output value control method that controls an output value of output information transmitted from each of transmission apparatuses, in which a transmission apparatus transmits the output information having a minimum output value as the output value to the other transmission apparatus, and when the output information does not reach the other transmission apparatus, the transmission apparatus repeats transmission of the output information after increasing the own output value by adding a predetermined value to a previous output value, and then the other transmission apparatus that has received the output information calculates the output value of the transmission apparatus, and notifies the calculated output value of the transmission apparatus as an appropriate output value to the transmission apparatus.

Abstract: The disclosure relates to a tunable 50 GHz and 100 GHz channel spacing DWDM transceiver, and methods of making and using the same. The transceiver comprises an electro-absorption modulation laser (EML), a system board configured to compare a preset wavelength with an actual emission wavelength of the EML, a microcontroller and one or more associated registers configured to communicate with the system board, a temperature controlling circuit configured to stabilize the actual emission wavelength of the EML; and a wavelength meter connected to the output of the EML and having an output connected to the system board. The system board may be configured to provide a feedback loop from the EML to the microcontroller. The transceiver, suitable for 50 GHz channel spacing standards, can be made from existing standard transceivers and can switch between 50 GHz and 100 GHz channel spacing modes.

Abstract: An optical communication module in which the pin arrangement can be applied flexibly. An optical communication module has an outer shape formed based on normal standards and which is able to communicate with a host-side circuit board, etc. to which it is fitted, via a predetermined communication interface; wherein the optical communication module exchanges input/output I/F information with the circuit board, etc., and the communication interface can be switched to another communication interface based on these input/output I/F information.

Abstract: A scheme is described of remote control of the slicing level of a receiver in a smart SFP (or SFP+, or XFP) duplex (or BiDi, or SWBiDi) transceiver in a communication system using an operating system with OAM and PP functions, an OAM, PP & Payload Processor, a transceiver, a BERT, and an optical link in the field.

Abstract: A bidirectional interface for multimode optical fiber includes a receive/transmit optical fiber port operable to connect to a multimode optical fiber, a wavelength separating module in communication with the receive/transmit optical fiber port, an optical receiver module in communication with the wavelength separating module and configured to receive optical signals at a first wavelength via the wavelength separating module and the receive/transmit optical fiber port, and an optical transmit module in communication with the wavelength separating module and configured to transmit at a second wavelength via the wavelength separating module and the receive/transmit optical fiber port.

Abstract: At the time of assembly of an optical transmission/reception module, a test variable wavelength light source 22 for outputting a test light signal is connected to a connector 8 of an optical fiber 7, and a large-diameter PD 23 measures a transmission loss in a light wavelength band limiting filter 12 while a rotational position determining unit 24 rotates a fiber ferrule 5, so that the rotational position determining unit 24 determines the rotational position ?loss-min of the fiber ferrule 5 which minimizes the transmission loss in the light wavelength band limiting filter 12, and aligns the fiber ferrule 5 at the rotational position ?loss-min.

Abstract: An optical transceiver device includes a transmitter, a first and a second optical circulators and a receiver. The transmitter transmits a light signal uploaded with an electrical signal. The first and second optical circulators each include three ports. The second port of the second optical circulator is configured for transmitting the light signal circulated via the first and second ports of the first optical circulator and the first port of the second optical circulator, and the third port of the second optical circulator is configured for receiving an incoming light signal. The receiver receives the incoming light signal circulated back via the first port of the second optical circulator, and the second and third ports of the first optical circulator and converts the incoming light signal to be an electrical signal.

Abstract: Methods, algorithms, architectures, circuits, and/or systems for determining the status of parameters associated with optical transceiver operation are disclosed. The optical transceiver can include an optical receiver to receive optical data; an optical transmitter to transmit optical data; one or more memories to store data (and, optionally, thresholds) for each of a plurality of parameters that are related to operation of at least one of the optical receiver and the optical transmitter; a microprocessor that compares the parametric data against the threshold(s) to calculate one or more flags to indicate whether a corresponding parameter has exceeded the first or second threshold; and an interface that receives a flag request from a host, and provides the one or more flags in response to the request. In the present disclosure, the microprocessor may calculate the one or more flags only in response to the flag request from the host.

Abstract: Monitoring signals associated with operating parameters of an optical transceiver are ascertained by using a comparator arrangement external to a micro-controller unit. Monitoring signals associated with these operating parameter are provided as inputs to a discrete arrangement of comparators and then evaluated against a known reference voltage source. The reference source is swept across a known range of values, and when the output of the comparator changes state, the value of the reference input associated with this transition is defined as the value of the specific monitoring input signal and stored within the proper memory location within the microcontroller portion of the transceiver monitor circuit. The digital output signal of the comparator is applied as an input to the microcontroller, which recognizes this digital signal as defining the specific value of the reference signal to use and equate with the value of the monitored signal.

Abstract: A system for transmitting data packets over a network. The system includes a plurality of first nodes, wherein each first node has a first transceiver configured to transmit a data packet at at least one of a plurality of first wavelengths and receive a data packet at an assigned first wavelength, wherein each first node is configured to pass incoming data packets not transmitted at the assigned first wavelength, a plurality of second nodes, wherein each second node has a second transceiver configured to transmit a data packet at least one of a plurality of second wavelengths and receive a data packet at an assigned second wavelength, wherein each second node is configured to pass incoming data packets not transmitted at the assigned second wavelength, and at least one optical fiber operably connecting the transceivers.

Abstract: Methods and systems are provided for extending the range that a laser can transmit data, particularly in environments with high attenuation or turbidity. Particularly, an energy storing laser that is capable of continuously converting electrical energy to optical energy and storing the optical energy or the electrical energy in the energy storing laser until the energy storing laser is instructed to transmit a laser transmission. In some embodiments, the energy storing laser uses a pulse train with a low duty cycle to increase the peak power of each laser pulse. Also, a pointing and tracking system is used to provide a communication link between stationary platforms or moving vehicles.

Abstract: A method, system, and apparatus for a uni-fiber laser communications (lasercom) terminal are disclosed herein. The apparatus includes an oscillator to generate a first signal having a first wavelength, and a modulator to modulate the first signal. The apparatus further includes a circulator to circulate the first signal, and a bi-directional optical amplifier (optical amp) to amplify the first signal. Also, the apparatus includes an optical fiber, which is embedded in a ferrule, and an end of the ferrule is coated with a reflective coating. Additionally, the apparatus includes at least one lens, where the first signal is transmitted through and received through the optical fiber and at least one lens. Also, the apparatus includes an acquisition detector to detect the first signal. Further, the apparatus includes an actuator associated with the ferrule to nutate and translate the ferrule according to feedback from the acquisition detector regarding the first signal.

Abstract: A Universal Serial Bus (USB) dongle may include an optical transceiver having a USB interface for engagement to an electronic device such as a laptop computer or other USB-configured device. The USB dongle may include a converter or buffering, isolation, modulation or amplification circuitry. The USB dongle sends and receives data signals which may be carried upon an optical transmission as generated by an LED light source which in turn is in communication with a host device such as a network processor. The USB dongle may also include operational amplifiers (op-amps) and transistor amplifiers.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is less than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: Adaptive power setting techniques for optical transceivers are provided. Optical signals are received at a first optical transceiver device that are transmitted from a second optical transceiver device. A receive power of the optical signals received at the first optical transceiver device from the second optical transceiver device is determined. A characteristic of optical signals transmitted by the first optical transceiver device to the second optical transceiver device is modulated to indicate to the second optical transceiver device a disparity of the receive power with respect to a target receive power level at the first optical transceiver device. Conversely, the first optical transceiver device adjusts a power level of optical signals transmitted by the first optical transceiver device to the second optical transceiver device based on a characteristic of the optical signals received at the first optical transceiver device.

Abstract: A photonic-cable assembly includes a power source cable connector (“PSCC”) coupled to a power receive cable connector (“PRCC”) via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

Abstract: An optoelectrical connector is composed of a plug to which a wire and an optical fiber are assembled and a receptacle to which the plug is inserted and connected. A receptacle includes insulation sleeves and conductive contacts in openings of receptacle housings, and plugs include a ferrule assembled bodies which are composed of an insulation ferrule which holds an optical fiber and a conductive cylindrical member which holds the ferrule and to which a wire is assembled, in an opening of the plug housing. When the plugs are inserted into the receptacle, the contacts and the cylindrical member contact with each other and the ferrules are inserted into the sleeves. Parts which serve electrical connection are not exposed.

Abstract: A digital coherent receiver converts signals and local light respectively detected, as detection results, in signal light from an optical transmission line, into digital signals and that further applies digital processing to the digital signals. The receiver includes a skew detecting unit that detects skew between the digital signals; a skew control unit controls the skew of each of the signals so that the skew to be detected by the skew detecting unit will be reduced; and a demodulating unit that demodulates each signal controlled for skew by the skew control unit.

Abstract: A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a liquid lens are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where a liquid lens is deployed with each of the one or more detectors. The method determines, for each of the detected signals, if the detected signal is out of focus, and applies a corrective voltage to each liquid lens that corresponds to a detected terahertz signal that is out of focus, wherein the corrective voltage adjusts a focus of the detected signal. The method measures a signal-to-noise ratio of the detected signals, and establishing a terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio.

Abstract: There is provided an optical transmitting device including a detector to detect a transmission rate of a transmission signal, a transmission method selector to determine a transmission method of the transmission signal, based on the transmission rate detected by the detector, a modulation signal generator circuit to generate a modulation signal from the transmission signal, based on the transmission method determined by the transmission method selector, and an optical modulator to generate a modulated optical signal from the modulation signal generated by the modulation signal generator circuit.

Abstract: A system configured to maintain a consistent local-oscillator-power-to-primary-signal-power ratio (LO/SIG ratio).

Abstract: In a Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) utilizing a conventional downstream optical signal reusing method, there is an inventory problem that different optical transmitter types need to be provided for the operation, management, replacement, etc. of a system. A WDM-PON system according to the present invention, includes: a seed light (SL) unit generating a seed light whose wavelength intervals and center wavelengths are adjusted using at least one seed light source; an optical line terminal (OLT) receiving the wavelength-multiplexed seed light from the seed light unit, transmitting a downstream optical signal to a subscriber of the WDM-PON, and receiving a upstream optical signal from the subscriber; and an optical network unit (ONU) receiving the downstream optical signal from the OLT, flattening and modulating the downstream optical signal with upstream data so that the downstream optical signal is reused for carrying upstream data.

Abstract: An optical transceiver configured to perform filtering of digital diagnostics prior to the filtered results being made accessible to a host computing system (hereinafter referred to simply as a “host”) that is communicatively coupled to the optical transceiver. The optical transceiver includes sensor(s) that measures analog operational parameter signals such as temperature and supply voltage. The analog signals are each converted to a plurality of digital samples by analog to digital converter(s). A processor executes microcode that causes the optical transceiver to perform filtering on the various samples. The optical transceiver may then make the filtered result accessible to the host.

Abstract: Consistent with the present disclosure, an optical communication system, such as a passive optical network (PON), is provided that includes an optical line terminal (OLT) and a plurality of optical network units (ONUs). The OLT includes a plurality of photonic integrated circuits that have both optical transmitters and receivers provided therein. Accordingly, the OLT may have fewer components and a simpler, more reliable and cost-effective design than a conventional OLT including discrete components. In addition, various ONU configurations are provided that also have a simple design and fewer components. Thus, ONUs consistent with the present disclosure may also have reduced costs.

Abstract: An optoelectronic device having an intelligent transmitter module (“ITM”) includes a mechanism for logging operational information regarding the ITM. The optoelectronic device includes a microcontroller and a persistent memory. The microcontroller is configured to identify the operational information, and write log information representing the operational information to the persistent memory. The operational information may include statistical data about operation, or may include measured parameters. Log entries may be made periodically and/or in response to events. The log may then be evaluated to determine the conditions under which the ITM has historically operated.

Abstract: In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.

Abstract: An equalization filter is provided for solving the problem in which there is a limited range in which compensated for distortion of a transmission signal can be made. Measuring instrument 104 measures a distortion quantity which characterizes distortion of the transmission signal. Comparator 105a generates a differential signal which indicates the difference between the transmission signal and a compensation signal. Delay device 105b delays the differential signal based on the distortion quantity measured by measurement instrument 104 and generates the compensation signal.

Abstract: A parallel optical transceiver module is provided that has a balanced laser driver arrangement. The balanced laser driver arrangement of the invention includes at least two laser diode driver ICs, which preferably are located on opposite sides of a laser diode IC. Each laser diode driver IC drives a subset (e.g., half) of the total number of laser diodes of the laser diode IC. Because each laser diode driver IC drives a subset of the total number of laser diodes of the laser diode IC, the pitch (i.e., distance) between the high-speed signal pathways within the laser diode driver ICs can be increased. Increasing the pitch between the high-speed signal pathways provides several advantages, including, for example, reducing the potential for electrical cross-talk and inductive coupling between adjacent wire bonds that connect the output driver pads on the driver IC to the respective input pads on the laser diode IC.

Abstract: An optical transceiver is disclosed in which the optical output thereof is controlled without degrading the signal quality. The optical transceiver of the invention includes a plurality of transmitter units and a controller that adjusts the bias current of respective transmitter units. The controller, receiving information to decrease/increase the output of the optical transceiver, decides a unique unit that has a largest margin to increase/decrease the bias current and provides a control signal only to the unique unit to increase/decrease the bias current.

Abstract: Disclosed is a method for setting a power control initial value by using an indication light in visible light communications and a transmission/reception (Tx/Rx) apparatus using the method. The method includes the steps of: radiating multiple indication lights having power levels different from one another by a visible light communication transmitter; aligning a communication position simultaneously with measuring Received Signal Strength Indication (RSSI) of the indication light on detecting the indication light, selecting a power level whose RSSI is in a preset threshold range and which is adequate for transmission/receive among the multiple power levels different from one another, and informing the visible light communication transmitter of the adequate power level by a visible light communication receiver; and transmitting data from the visible light communication transmitter to the visible light communication receiver by using a transmitted power initial value according to a selected power level.

Abstract: In one aspect, the present invention embraces a wavelength locking method for causing a narrow-band wavelength spectrum of an optical transmit signal of an optical transceiver device to track a narrow-band wavelength spectrum of an optical receive signal received by the optical transceiver device Further, the present invention embraces a wavelength lockable optical transceiver device, especially for a passive optical transmission network, using this wavelength locking method.