Abstract: A near-eye imaging system includes a light source, a waveguide, a scanner, and a sensor. The light source is configured to emit light. The waveguide includes an output coupler. The scanner is configured to direct the light to the output coupler at varying scan angles. The waveguide confines the light to guide the light to the output coupler. The output coupler has negative optical power and is configured to direct the light to exit the waveguide as expanding illumination light toward an eyebox region. The sensor is configured to generate a tracking signal in response to returning light incident on the sensor via the scanner and via the output coupler.

Abstract: An optical fiber fuse protection device includes an upstream optical fiber disposed on an upstream side, a downstream optical fiber disposed on a downstream side, and a wall interposed between a part of the upstream optical fiber and a part of the downstream optical fiber. The downstream optical fiber is fusion-spliced to the upstream optical fiber and is made of a single optical fiber or a plurality of optical fibers fusion-spliced to each other.

Abstract: A detection system for measuring one or more conditions within an area. At least one fiber optic cable transmits light wherein the at least one fiber optic cable defines a plurality of nodes arranged to measure the one or more conditions. A control system communicates with the at least one fiber optic cable such that scattered light and a time of flight record is transmitted from the at least one fiber optic cable to the control system. The control system includes a detection algorithm operable to identify a portion of the scattered light associated with each of the plurality of nodes. When determining an alert, the control system transmits data associated with a presence and magnitude of the one or more conditions at each of the plurality of nodes to a cloud computing environment and, in return, receives a notification based on the data transmitted.

Abstract: Two photoelectric circuit sets each have a light source, two light switches, optical fibers, photoelectric sensor and computer. The light source emits visible light to the first switch, which is continuously deflected and reflected by a torsional micro-mirror. The light respectively irradiates each of the optical fibers in a composite material optical fiber prepreg layer. If the material is normal, the optical fiber is not damaged, the visible light passes through the optical fiber and irradiates the second switch, and is continuously deflected and reflected by a second torsional micro-mirror, the light irradiates the photoelectric sensor. The sensor outputs an electric signal to the computer. If the material is damaged, the optical fiber here is damaged, another corresponding optical fiber path at an intersection point is also damaged without electric signal output. The computer gives breaking position coordinates at the intersection point of two paths of optical fiber arrays.

Abstract: A fault location in an optical cable at a long distance is easily measured and detected with low-cost equipment in a configuration in which an isolator is disposed in the vicinity of an optical amplifier for improved optical transmission performance and for stabilization. An optical amplifier has a configuration in which multiplexing/demultiplexing units as first WDM filters and that multiplex/demultiplex main signal light and OTDR light and (measurement light) for submarine cable fault measurement transmitted to a submarine cable in opposite directions from a transmission device side and a reception device side, transmit the multiplexed/demultiplexed main signal light to a main path passing through an isolators and an EDF, and transmit the multiplexed/demultiplexed OTDR light to a bypass path bypassing the isolators and the EDF are included on both sides of a set of the isolators and the EDF of the submarine cable.

Abstract: Methods and systems to detect power outage are provided herein. The system includes a Cable Modem Termination System (CMTS) to periodically poll cable modems and determine cable modems of the plurality of cable modems that are offline based on the poll. The system correlates and aggregates locations of the cable modems that are offline to determine a geographic area where a percentage of the cable modems that are offline is higher than a predetermined threshold. A report is generated indicating a power outage in the geographic area when the percentage is above the predetermined threshold.

Abstract: An optical transmission apparatus includes the optical transceiver configured to generate a test light for each wavelength assignable to the wavelength multiplex light to transmit the test light to the optical transmission line via the wavelength multiplexer and demultiplexer, detect a reflected light for the test light from the optical transmission line, calculate an arrival distance of the test light for the each wavelength from the reflected light for the each wavelength, and set a wavelength having a longest arrival distance among the arrival distances for the respective wavelengths, as a wavelength to be assigned to the signal light in the optical transceiver.

Abstract: In some examples, an optical time-domain reflectometer (OTDR) device may include a laser source to emit a plurality of laser beams. Each laser beam may include a different pulse width. A control unit may analyze, for each laser beam, a backscattered signal from a device under test (DUT). The control unit may generate, for each backscattered signal, a trace along the DUT. Further, the control unit may generate, based on an analysis of each trace along the DUT, a combined trace that identifies optical events detected along the DUT.

Abstract: In some examples, an optical time-domain reflectometer (OTDR) device may include a laser source to emit a laser beam into a device under test (DUT), and a connection port to connect the OTDR device to a first end of the DUT, where the OTDR device may be designated a first OTDR device. A sensor display generator may determine a length of the DUT, receive, from a second OTDR device connectable to a second opposite end of the DUT, and over the DUT, OTDR information acquired by the second OTDR device in a direction from the second OTDR device towards the first OTDR device, and ascertain, based on acquisition by the first OTDR device, further OTDR information in a direction from the first OTDR device towards the second OTDR device. The sensor display generator may generate a bi-directional combined schematic display that includes relevant optical events with respect to the DUT.

Abstract: A system and method for providing haptic counteractions and alerts within a seat of a vehicle that include determining that at least one front seat passenger is occupying at least one front passenger seat and at least one rear seat passenger is occupying at least one rear passenger seat. The system and method also include determining a location of the at least one rear seat passenger with respect to a location of the at least one front seat passenger within the vehicle and determining if at least one disturbance is affecting the at least one front passenger seat. The system and method further include actuating at least one vibrational element to counteract the at least one disturbance affecting the at least one front passenger seat and to provide a reminder alert pertaining to the at least one rear seat passenger to the at least one front seat passenger.

Abstract: A transceiver card for a telecommunications box for transmitting data over a first optical fiber and receiving data over a second optical fiber. The card has transmitter for transmitting data over the first optical fiber, the transmitter having a laser and a modulator, a fiber output optically connected to the laser for connecting the first optical fiber to the card, a fiber input for connecting the second optical fiber to the card, a receiver optically connected to the fiber input for receiving data from the second optical fiber, and an OTDR optically connected between the transmitter and the fiber output or between the receiver and the fiber input. An energy level detector is also provided between the receiver and the fiber input.

Abstract: A sensing optical fiber acoustic emission integrated sensing system and method for monitoring the safety of a structure which comprises a sensing optical fiber temperature interference removal device and a sensing optical fiber acoustic emission demodulation device. A sensing optical fiber (206) successively passes through the sensing optical fiber temperature interference removal device and the sensing optical fiber acoustic emission demodulation device. A distributed sensing optical fiber acoustic emission regulation and control device for sensing the degradation of structure performance is integrated with a sensing optical fiber acoustic emission sensing system with multiple complex devices, multiple functional modules and multiple interconnection components.

Abstract: A structural health monitoring system includes a first component and a second component associated at a joint. At least one sensor is embedded within the joint to monitor a health of at least one of the first component, the second component, and the joint.

Abstract: An OTDR system utilizes a laser source that is turned “on” and kept powered until its light reaches the end of the fiber span being measured (i.e., until the fiber span is fully illuminated). At any point in time after the fiber is fully illuminated, the laser source can be turned “off”. The return (reflected and backscattered) signal is directed into a photodetector of the OTDR, and is measured from the point in time when the fiber span starts to be illuminated. The measurements are made by sampling the return signal at predetermined time intervals—defined as the sampling rate. The created power samples are then subjected to post-processing in the form of a differentiation operation to create a conventional OTDR trace from the collected data.

Abstract: A transceiver card for a telecommunications box for transmitting data over a first optical fiber and receiving data over a second optical fiber. The card has transmitter for transmitting data over the first optical fiber, the transmitter having a laser and a modulator, a fiber output optically connected to the laser for connecting the first optical fiber to the card, a fiber input for connecting the second optical fiber to the card, a receiver optically connected to the fiber input for receiving data from the second optical fiber, and an OTDR optically connected between the transmitter and the fiber output or between the receiver and the fiber input. An energy level detector is also provided between the receiver and the fiber input.

Abstract: A transceiver card for a telecommunications box for transmitting data over a first optical fiber and receiving data over a second optical fiber. The card has transmitter for transmitting data over the first optical fiber, the transmitter having a laser and a modulator, a fiber output optically connected to the laser for connecting the first optical fiber to the card, a fiber input for connecting the second optical fiber to the card, a receiver optically connected to the fiber input for receiving data from the second optical fiber, and an OTDR optically connected between the transmitter and the fiber output or between the receiver and the fiber input. An energy level detector is also provided between the receiver and the fiber input.

Abstract: An optical fiber assembly includes a central optical fiber core having a longitudinal axis surrounded by a cladding layer along the longitudinal axis, a distal end portion and a proximal end portion; it further comprises a layer of a material at least partially surrounding the cladding layer; the layer of material may be light-sensitive; and, at least two electrodes may be embedded at least partially along the longitudinal axis within the layer of light-sensitive material. The light-sensitive material may be a photoresist material, and the photoresist material characteristics change proportional to the amount of light impinging on the photoresist material. These characteristics may include one or more of electrical resistance changes or voltage changes.

Abstract: A light device, notably for a motor vehicle including at least one laser light source emitting a laser light beam, a wavelength conversion material capable of converting one part of a laser light beam, diffusing another part of the laser light beam and combining the diffused and converted parts into a resultant primary light beam, a movable scanning means for scanning the laser light beam onto the wavelength conversion material, an optical means of projection of the primary light beam, an optical fiber arranged for receiving on an input face the laser light beam emitted by the laser light source and for directing the laser light beam toward the movable scanning means.

Abstract: The imaging apparatus comprises an image sensor and a controller. In the image sensor, charge accumulation and reading out in a plurality of pixels arranged in a two-dimensional array are controlled per line. The controller identifies one or more lines from lines of the image sensor to generate control information for controlling illumination light on the basis of the one or more lines identified.

Abstract: Optical time domain reflectometer (OTDR) systems, methods and integrated circuits are presented for locating defects in an optical cable or other optical cable, in which a first optical signal is transmitted to the cable and reflections are sampled over a first time range at a first sample rate to identify one or more suspected defect locations, and a second optical signal is transmitted and corresponding reflections are sampled over a second smaller time range at a higher second sample rate to identify at least one defect location of the optical cable for relaxed memory requirements in the OTDR system.

Abstract: An optical receiver module that receives a wavelength multiplexed light and a process to assemble the optical receiver module are disclosed. The optical receiver module provides a coupling unit to collimate the wavelength multiplexed light and a device unit that installs an optical de-multiplexer and photodiode elements within a housing. The front wall of the housing through which the wavelength multiplexed light passes is polished in a right angle with respect to the bottom of the housing.

Abstract: The present disclosure includes systems and methods for testing bundles of fiber optic fibers, such as fiber optic trunk cables, for correct polarity of connections at each end of the bundle of fibers while preventing the fiber optic fibers from contacting any other components during testing. The systems include a processor, a plurality of signal generators interfaced with a plurality of signal generator ports, a sensor interfaced with a sensor input port, a first selector switch, and a display, the processor operable to stimulate the plurality of signal generators one at a time in a first sequence to produce a signal, the first sequence based on a position of the first selector switch, the processor further operable to cause the display to display an output of the sensor.

Abstract: An optical time domain reflectometer (OTDR) system with an integrated high speed optical modulator is capable of operating at a speed similar to the OTDR pulse width to improve the measurement resolution and reduce the time required to acquire a high dynamic range OTDR measurement over existing approaches. ASICs can be used to control the modulator and generation of pulses. The high-speed optical modulator enables high resolution single-photon OTDR measurement by blocking out all return light except from the region of fiber under examination.

Abstract: A transceiver card for a telecommunications box for transmitting data over a first optical fiber and receiving data over a second optical fiber. The card has transmitter for transmitting data over the first optical fiber, the transmitter having a laser and a modulator, a fiber output optically connected to the laser for connecting the first optical fiber to the card, a fiber input for connecting the second optical fiber to the card, a receiver optically connected to the fiber input for receiving data from the second optical fiber, and an OTDR optically connected between the transmitter and the fiber output or between the receiver and the fiber input. An energy level detector is also provided between the receiver and the fiber input.

Abstract: A tamper seal includes an optical waveguide arranged to guide a propagating light-beam along a propagation direction. First and second portions of the tamper seal are configured to be arranged on first and second parts, respectively, which are movable relative to each other. The first portion has an input coupler arranged to couple incident light into the optical waveguide, and the second portion has at least one output coupler arranged to couple out of the optical waveguide at least partially light guided in the optical waveguide. The input coupler, the optical waveguide, and the output coupler are configured to transmit light from the input coupler to the output coupler. The waveguide is configured to be disruptable and includes a layer having a distinctive appearance that is changed in response to an at least partial disruption of said optical waveguide.

Abstract: A bonded structure includes a first member, a second member, an adhesive that bonds the first member and the second member together, and an optical fiber sandwiched between the first member and the second member. When pressure is applied to the optical fiber only from a predetermined direction, the sectional shape of the optical fiber changes to an elliptical shape, so that birefringence occurs, whereby the shape of the light spectrum changes so as to have multiple peaks. The optical fiber is used as a sensor for detecting the bonding condition between the first member and the second member based on the birefringence.

Abstract: A device includes a processor, a light emitter coupled to the processor, and a memory. The light emitter is configured to generate a first light to be provided to an optical fiber at a first time when a portion of the optical fiber has a first physical configuration and to generate a second light to be provided to the optical fiber at a second time when the portion of the optical fiber has a second physical configuration. The memory stores instructions executable by the processor to determine a first estimated distance associated with a first location of the optical fiber based on the first light, determine a second estimated distance associated with a second location of the optical fiber based on the second light, determine a third estimated distance associated with a third location of the optical fiber based on the first estimated distance and the second estimated distance.

Abstract: A system of delivering power by light, through a fiber. A system for remote operation of an instrument includes a fiber-coupled power laser source, which has an output fiber with a first core diameter. A fiber taper having a wide end and a narrow end, is used to connect the fiber-coupled power laser source to a system fiber having a second core diameter less than the first core diameter. The system fiber delivers optical power to the remote module, in which a fiber-coupled photovoltaic assembly having an input fiber connected to the system fiber, converts the received light to electrical power. The photovoltaic assembly has a first electrical output and a second electrical output, and the photovoltaic assembly is configured to supply power at a first voltage at the first electrical output, and to supply power at a second voltage at the second electrical output.

Abstract: A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.

Abstract: A transceiver card for a telecommunications box for transmitting data over a first optical fiber and receiving data over a second optical fiber. The card has transmitter for transmitting data over the first optical fiber, the transmitter having a laser and a modulator, a fiber output optically connected to the laser for connecting the first optical fiber to the card, a fiber input for connecting the second optical fiber to the card, a receiver optically connected to the fiber input for receiving data from the second optical fiber, and an OTDR optically connected between the transmitter and the fiber output or between the receiver and the fiber input. An energy level detector is also provided between the receiver and the fiber input.

Abstract: An optical pulse compression reflectometer is provided, which comprises: a single wavelength continuous optical source, an optical splitter, a modulation frequency pulse generating module, an optical directional coupler, an optical fiber under test, an optical coupler, a balanced photoelectric detector, and a pulse compression processing module. The present invention, in addition to overcoming the contradictory constraint between spatial resolution and measurement range in traditional time domain reflectometry and giving to full play the super spatial resolution from frequency modulation technology, has a longer measurement range than that in the optical frequency domain reflectometry.

Abstract: A fiber optic security system is provided. The fiber optic security system includes at least one length of fiber optic cable affixed to at least one item to be monitored using the fiber optic security system. The fiber optic security system also includes at least one local control node, the at least one local control node including at least one light source for generating and transmitting light through the at least one length of fiber optic cable, and the at least one local control node monitoring a status of the light. The fiber optic security system also includes a remote control unit for receiving information from the at least one local control node regarding the status of the light.

Abstract: A system and method for detecting tampering are disclosed. In one aspect, the system includes an optical fiber with a first end and a second end, the optical fiber conformed to an object. The object includes a container having multiple parts that physically alter the optical fiber when the container or at least one of the multiple parts is tampered with. The system also includes a detachable light source configured to emit a light pulse, the optical fiber configured to receive the light pulse at the first end and emit an optical signature at the second end. The system further includes a detachable optical spectral analyzer configured to capture a current optical signature from the second end, the optical spectral analyzer in communication with a data store.

Abstract: According to a method according to the invention for operating an additional tool axis (Z) of a tool (2) guided by a manipulator, in particular a robot (1), a position and/or an orientation of the tool in space are defined by axis positions (q1-q6) of the manipulator axes and a position value (f) of the tool axis, are saved and/or displayed, with an automatic conversion being carried out between the position value (f) and an axis position (e) of the tool axis which brings it about.

Abstract: A correlation optical time domain reflectometer (OTDR) provides a correlation sequence that is continuously transmitted along a fiber for testing the fiber for anomalies. Such continuous transmission can result in beat noise that degrades the quality of the measured returns. In this regard, each sample is composed of backscatter returns from many points along the fiber that arrive at the OTDR at the same time. When a subset of these returns have frequency differences that appear in the passband of the OTDR receiver, the constructive and destructive interference of these returns at the OTDR receiver can cause significant low-frequency beat noise in the OTDR signal. An optical transmitter is configured to transmit the correlation sequence through the fiber using a wideband optical signal such that the beat noise is suppressed within the passband of the OTDR receiver, thereby improving the quality of the returns measured by the OTDR.

Abstract: A method and system for recognizing and verifying the identity of a driver and front seat passenger of a vehicle. A vehicle owner uploads profile data for several individuals who may be a driver or passenger to a database in the vehicle. When a driver or passenger enters the vehicle, the system uses the profile data—which can include height, weight, and gender information about the individual—along with vehicle data such as seat position, to identify the driver or passenger from the database. The profile data for the known individual is then used to adjust the position of the seat and other components in the cockpit. The profile data is also used by various safety and convenience systems onboard the vehicle.

Abstract: The present invention provides an optoelectronic module including a substrate, an optoelectronic device and a control unit. The substrate includes a top surface, a bottom surface, a concave structure, a through hole structure and a conductive material. The concave structure is disposed on the top surface. The through hole structure passes through the substrate from the top surface to the bottom surface. The conductive material is filled into the through hole structure. The optoelectronic device is disposed on the substrate for providing or receiving an optical signal. The control unit is configured on the top surface and electrically connected to the conductive material and the optoelectronic device for controlling the optoelectronic device.

Abstract: An optical fiber having at least one fiduciary mark is provided. The at least one fiduciary mark is located at one or more axial positions along the optical fiber. The at least one fiduciary mark is configured to produce at least one change in a Rayleigh backscattering signal in the optical fiber. The at least one change in a Rayleigh backscattering signal may be an abrupt change in the Rayleigh backscattering signal. The abrupt change in the Rayleigh backscattering signal occurs over a length of the optical fiber that is of the order of or less than a spatial resolution of an interrogation system employed to detect the Rayleigh backscattering signal.

Abstract: An optical transmission system includes an optical transmission apparatus and an optical receiving apparatus. The optical transmission apparatus includes a transmitting unit that transmits signal light to the optical receiving apparatus through an optical transmission path, and a determining unit that determines continuity of the optical path using return light that returns from the optical receiving apparatus to the optical transmission apparatus through the optical transmission path, out of the signal light. The optical transmission apparatus includes a modulating unit that modulates a part of the signal light that is transmitted from the optical transmission apparatus through the optical transmission path to generate the return light, and an output unit that outputs the return light to the optical transmission apparatus through the optical transmission path.

Abstract: Devices and methods for optical measurements in point-to-point and point-to-multipoint networks, e.g. like PON networks with splitters are described in which reflected power from some known reflections at the end of the lines is used to determine the attenuation and stability of the attenuation of each line. Also a reference reflection is used at the beginning of the network so that an absolute loss measurement between the points of reflection and the reference reflection can be made. In a further aspect wavelength selective stable reflections and reflectors are used, to provide reflections in a wavelength range that does not interfere with normal operation.

Abstract: A lighting apparatus includes a laser light modification unit for modifying laser light from a laser to form a modified light. The lighting apparatus further includes a first layer and an opposing second layer, where the laser light modification unit is between the first and second layers. One of these two layers includes a transparent material being transparent to the modified light. The laser light modification unit is configured to allow the modified light to pass through the transparent material.

Abstract: A method, apparatus and system for minimally intrusive fiber identification includes imparting a time-varying modulation onto an optical signal propagating in an optical fiber and subsequently detecting the presence of the time-varying modulation in the optical signal transmitting through the fiber to identify the fiber. In a specific embodiment of the invention, a time-varying curvature is imposed on the fiber to be identified and the presence of the resultant time variation in the transmitted power of a propagating optical signal is subsequently detected for identification of the manipulated fiber.

Abstract: A first optical time domain reflectometer (OTDR) connects at a first location along an optical path between multiple optical transmitters and multiple optical receivers in an optical network. An optical filter, connects along the optical path, and includes multiple selectable optical wavelength blockers. A set of different length optical fibers is installed in multiple last fiber legs in the optical path. A controller selects ones of the multiple selectable wavelength blockers of the optical filter for insertion in the optical path; instructs the first OTDR to inject a first OTDR signal at the first location; receive, from the first OTDR, indications of whether a reflection of the first OTDR signal was received from each of the multiple optical receivers; and identifies faults in the optical network based on the received indications whether the reflection of the first OTDR signal was received from each of the multiple OTDR reflectors.

Abstract: The invention is a fiber optic cable calibration standard in combination with a device for calibrating distance and attenuation parameters of an optical time domain reflectometer (OTDR). The calibration standard includes a fiber optic cable spool assembly and inspection apparatus. The invention is also a calibration method. An OTDR to be calibrated against a National Institute of Standards and Technology (NIST) standard.

Abstract: A system for fault recovery in an optical network may include an initial loading equipment (ILE) apparatus configured to supply power to a set of channels over a first communications link of the optical network, the set of channels including data channels and spare channels, and a control system configured to detect an optical power level over the data channels of the first communications link and determine whether a Q-factor corresponding to the data channels of the first communications link is below an error correction threshold, the control system configured to alert the ILE apparatus to adjust its optical power output over the spare channels upwardly based on the determination that the Q-factor is below the error correction threshold to increase the Q-factor.

Abstract: A time-resolved photoluminescence-based system providing quality control during manufacture of thin film absorber layers for photovoltaic devices. The system includes a laser generating excitation beams and an optical fiber with an end used both for directing each excitation beam onto a thin film absorber layer and for collecting photoluminescence from the absorber layer. The system includes a processor determining a quality control parameter such as minority carrier lifetime of the thin film absorber layer based on the collected photoluminescence. In some implementations, the laser is a low power, pulsed diode laser having photon energy at least great enough to excite electron hole pairs in the thin film absorber layer. The scattered light may be filterable from the collected photoluminescence, and the system may include a dichroic beam splitter and a filter that transmit the photoluminescence and remove scattered laser light prior to delivery to a photodetector and a digital oscilloscope.

Abstract: The present disclosure describes an apparatus including a composite panel. The apparatus includes a first composite panel including a first optical fiber embedded therein, the first optical fiber being arranged in a pattern, and a first input port connected to a first end of the first optical fiber, the first input port configured to receive an optical signal from an optical time domain reflectometer. The optical time domain reflectometer is configured to send the optical signal through the first input port and measure a strength of a reflected optical signal that is reflected back from the first optical fiber, wherein the strength indicates a measured optical impedance of the first optical fiber. A measured optical impedance that is substantially the same as a baseline optical impedance for the fiber indicates no damage, while a measured optical impedance that differs from the baseline optical impedance by a predetermined threshold indicates damage.

Abstract: A method includes applying pulsed light to a first end of an optical fiber from an optical fault locator during a first distance test. The method includes determining an estimated distance to a fault based on the pulsed light. The method includes sending information indicative of the estimated distance to a remote device. The method also includes applying first visible light from the optical fault locator to the first end of the optical fiber to facilitate identification of the fault at a first site that is remote from the first end of the optical fiber.

Abstract: An apparatus comprising an optical transmitter, a coarse tuner coupled to the optical transmitter and having a first tuning range, a fine tuner coupled to the optical transmitter and having a second tuning range smaller than and within the first tuning range, a wavelength division demultiplexer coupled to the optical transmitter and to a plurality of optical fibers, and a detector coupled to the optical transmitter and the wavelength division demultiplexer.

Abstract: An apparatus comprising an optical transmitter, a coarse tuner coupled to the optical transmitter and having a first tuning range, a fine tuner coupled to the optical transmitter and having a second tuning range smaller than and within the first tuning range, a wavelength division demultiplexer coupled to the optical transmitter and to a plurality of optical fibers, and a detector coupled to the optical transmitter and the wavelength division demultiplexer. A network component comprising at least one processor configured to implement a method comprising detecting an Optical Time Domain Reflectometry (OTDR) signal spectrum that has a modulated pattern, and detecting a reflected OTDR signal spectrum that has a shifted modulated pattern comprising a frequency shift with respect to the OTDR signal spectrum and a time shift proportional to the frequency shift.