Abstract: A method for measuring a response from an optical fiber providing distributed back reflections using a system comprising an optical source comprising a laser, an optical receiver and a processing unit is disclosed. The method comprises generating an interrogation signal and an optical local oscillator using the optical source, the interrogation signal being represented by an interrogation phasor and the optical local oscillator being represented by a local oscillator phasor; transmitting the interrogation signal into the optical fiber; and mixing the optical local oscillator with reflected light from the optical fiber and detecting a mixing product with the optical receiver to achieve a receiver output signal.

Abstract: A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a photodetection unit, and an operation unit. The pulse forming unit forms a light pulse train including a plurality of light pulses having time differences and center wavelengths different from each other from a measurement target light pulse output from a pulsed laser light source. The correlation optical system receives the light pulse train output from the pulse forming unit and outputs correlation light including a cross-correlation or an autocorrelation of the light pulse train. The photodetection unit detects a temporal waveform of the correlation light output from the correlation optical system. The operation unit estimates a wavelength dispersion amount of the pulsed laser light source based on a feature value of the temporal waveform of the correlation light.

Abstract: An optical monitoring system serves to monitor surroundings, having a monitoring apparatus, the visual or scanning field of which is captured by a lens, and a protection panel (112) which protects the lens from precipitation and covers at least the visual or scanning field of the monitoring apparatus. In order to avoid the signal quality of the monitoring apparatus being impaired by precipitation on the protection panel, it is proposed that the protection panel (12; 112; 218; 318) is acoustically coupled to at least one ultrasonic transducer (10). The optical monitoring system can be included into the control system of a vehicle for autonomous driving, wherein, overall, it is possible to obtain increased safety of the control system.

Abstract: A method performed in a coating testing system for automatically determining the polymerisation of coating material includes positioning a spectrometer probe adjacent to an object (wire 10), the object comprising a polymer coating; acquiring spectra of the polymer coating using the probe; and performing chemometric analysis on the acquired spectra in order to measure the polymerisation of the polymer coating.

Abstract: In some examples, parallel optics based optical time domain reflectometer acquisition may include a laser array operatively collimated to an optical fiber array to transmit, in parallel, a plurality of laser beams to optical fibers of the optical fiber array. A photodiode array may receive, in parallel, backscattered and reflected light from the optical fiber array. The photodiode array may determine, based on the backscattered and reflected light, properties of the optical fibers of the optical fiber array.

Abstract: An in situ leakage detection system for protecting and monitoring buried non-metallic pipelines is provided. The system includes flexible composite mats arranged below and above the pipeline. Sensors, including, distributed optical fiber sensors (DOFS) are affixed to the pipe-facing mat surfaces and extend lengthwise along the pipeline. An optical time domain reflectometry (OTDR) reading unit is configured to provide optical signals to the DOFS and analyze the returned optical signal. The OTDR unit can measure frequency and amplitude of anti-Stoke components of Raman scattering signals and a time-distance of the signals to detect localized changes in temperature along the pipeline. The system is further configured to detect leaks and determine a location of the leaks from the foregoing temperature changes and time-distance information. A method of installing and operating an in situ leakage detection system is also provided.

Abstract: A device may receive, from a sensor device, cable distance data identifying cable distances along the fiber cable to vibrations experienced by the fiber cable from a vibration device. The device may receive location data identifying geographic coordinates associated with the vibrations, and may correlate the cable distance data and the location data to generate correlated data. The device may receive, from the sensor device, data identifying a cable distance along the fiber cable to an alarm condition associated with the fiber cable, and may determine geographic coordinates associated with the alarm condition based on the correlated data and the data identifying the cable distance along the fiber cable to the alarm condition. The device may perform actions based on the geographic coordinates associated with the alarm condition.

Abstract: The invention discloses an underwater umbilical cable which is capable of temperature and vibration measuring and three-dimensional shape reconstruction, wherein underwater umbilical cable is used to connect underwater equipment and aquatic equipment; the underwater umbilical cable comprises an outer sheath, armored steel wires, an inner sheath, a power cable, a communication optical cable, a steel pipe, three strain measuring optical fibers, three temperature measuring optical fibers, a distributed optical fiber strain interrogator, a distributed optical fiber temperature interrogator and a processor. The invention can collect the operation status data of the umbilical cable for a long time. The collected data is highly objective, can truly reflect the real-time operation status of the umbilical cables, and plays an important role in guaranteeing the long-term submarine oil and gas exploitation.

Abstract: The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Brillouin scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.

Abstract: There is provided a light receiving device including: a pixel including a first tap configured to detect a charge photoelectrically converted by a photoelectric conversion unit, and a second tap configured to detect a charge photoelectrically converted by the photoelectric conversion unit; a first comparison circuit configured to compare a first detection signal detected by the first tap and a reference signal; a second comparison circuit configured to compare a second detection signal detected by the second tap and the reference signal; a first zero reset signal generation circuit configured to generate a first zero reset signal that is supplied to the first comparison circuit when the first comparison circuit performs an auto zero operation; and a second zero reset signal generation circuit configured to generate a second zero reset signal that is supplied to the second comparison circuit when the second comparison circuit performs an auto zero operation.

Abstract: A method for determining the refractive index profile of a preform when the RIP is not substantially step-index like. (a) The preform deflection function is measured and transformed into a measured RIP. (b) A RI level and radius are assumed for the preform layer being evaluated and a compensation level RIP is calculated. (c) A theoretical deflection function is generated corresponding to the assumed RI level and radius and the generated data are transformed into a fitting RIP. (d) The fitting RIP is compared to the measured RIP and the comparison is evaluated against a predetermined accuracy level for the preform layer being evaluated. (e) Steps (b) and (c) are repeated iteratively until the predetermined accuracy level has been achieved. Steps (b) through (e) are repeated for each preform layer that needs to be compensated. Finally, a measurement artifact compensated refractive index profile is calculated for the preform.

Abstract: A light intensity distribution measurement apparatus is presented that is capable of accurately measuring the intensity of light in each mode at each position of an optical fiber through which light is propagated in a plurality of modes.

Abstract: A measurement system is described. The measurement system includes a test-and-measurement (T&A) circuit and an error analysis circuit. The T&A circuit is configured to generate measurement data. The measurement data includes at least one of analysis data and configuration data. The analysis data is associated with an analysis of at least one input signal. The configuration data is associated with at least one of a physical measurement setup of the measurement system and measurement settings of the measurement system. The T&A circuit further is configured to generate a graphic representation of the measurement data. The error analysis circuit is configured to identify errors or anomalies associated with the measurement data based on the graphic representation. Further, a measurement method is described.

Abstract: Embodiments discussed herein refer to LiDAR systems that use avalanche photo diodes for detecting returns of laser pulses. The bias voltage applied to the avalanche photo diode is adjusted to ensure that it operates at desired operating capacity.

Abstract: A measurement method and apparatus for determining power levels of pulsed power signals, wherein the pulsed power signals are needed for some applications with a high dynamic range and a high speed simultaneously. The apparatus and the measurement method particularly used to evaluate a performance of fiber optic sensors, optical pulse generators, switching devices and debugging other pulsed power systems.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing (DFOS) systems, methods, and structures that advantageously provide traffic monitoring, and traffic management which improves the safety and efficiency of a roadway.

Abstract: Aspects of the invention relate to systems, devices and methods for performing a surgical step or surgical procedure with visual guidance using an optical head mounted display.

Abstract: A system includes an optical module for supplying a Stokes light, a pump light and a probe light for generating a CARS light is provided. The optical module includes a fiber laser module and an optical plate. The fiber laser module includes an oscillator, a generator, a first amplifier, a second amplifier and a LD power distributor that is configured to distribute a laser power from a first laser diode to the oscillator as an oscillation source, to the generator as a pump power, to the first preamplifier as a pump power and to the second preamplifier as a pump power.

Abstract: An object is to provide an optical fiber route search method, an optical fiber route search device, and a program that can efficiently confirm a path of an optical fiber that is installed over a long distance or across a large range. The optical fiber route search method according to the present invention carries out optical measurement that performs distributed measurement of the state of an optical fiber while applying a disturbance to the optical fiber in a portion in which wires of the optical fiber are parallel to each other, branch out, or intersect with each other (a proximity portion), and determines that the position in which the number of singularities (peaks or intensity fluctuations) fluctuates (becomes plural) is the position of the proximity portion from a distribution diagram obtained through the optical measurement.

Abstract: An Optical Time Domain Reflectometer (OTDR) module obtains Optical Return Loss (ORL) of a fiber plant. Calibration information is obtained of at least internal OTDR reflections associated with the OTDR module. The OTDR module is connected to the fiber plant. An ORL response is measured due to reflections of an ORL signal transmitted from the OTDR module along the fiber plant, and a peak OTDR response is measured in response to reflections of an OTDR signal transmitted from the OTDR module along the fiber plant. A corrected ORL response of the fiber plant is determined by: using the measured peak OTDR response (e.g., peak value or area under the peak) and the calibration information to calculate the calculated ORL due to internal reflections, and then adjusting the measured ORL response by the calculated ORL to represent the corrected ORL of the fiber plant.

Abstract: Example embodiments add an optical amplifier to an multi-channel, continuously swept OFDR measurement system, adjust amplified swept laser output power between rising and falling laser sweeps, and/or utilize portions of a laser sweep in which OFDR measurements are not typically performed to enhance the integrity of the OFDR measurement system, improve the performance and quality of OFDR measurements, and perform additional measurements and tests.

Abstract: A photonic system includes a light source and a photonic structure. The photonic structure includes an optical transmission structure and an optical absorption structure. The optical transmission structure is configured to transmit light associated with a first wavelength range. The optical absorption structure is configured to absorb light associated with a second wavelength range. The light source is configured to provide a light beam with a wavelength that is within the second wavelength range to the optical absorption structure. The optical absorption structure is configured to generate and provide heat to the optical transmission structure when the light beam falls incident on the optical absorption structure.

Abstract: A reflectometer for allowing a test of a device, the reflectometer comprising: a source of pulsed radiation; a first photoconductive element configured to output a pulse in response to irradiation from the pulsed source; a second photoconductive element configured to receive a pulse; and a transmission line arrangement configured to direct the pulse from the first photoconductive element to the device under test and to direct the pulse reflected from the device under test to the second photoconductive element. At least one of the first and second photoconductive elements is provided on a different substrate to that of the transmission line arrangement.

Abstract: Provided is an optical communication system configured as an optical ring network including: a first optical communication device configured to transmit a first optical signal having a first wavelength in a first direction, and to transmit a second optical signal having a second wavelength in a second direction opposite to the first direction; and a second optical communication device configured to generate a first reflected signal by reflecting the first optical signal when the first optical signal is received, to generate a second reflected signal by reflecting the second optical signal when the second optical signal is received, and to transmit the first and second reflected signals to the first optical communication device, wherein the first optical communication device analyzes a connection state of the second optical communication device based on the first and second reflected signals.

Abstract: An optical test instrument, in combination with a removable connector cartridge is provided. A method of replacing a damaged or worn optic fiber interface is also provided. The optical test instrument has casing having a cartridge receiving cavity therein with an inner end provided with a test instrument optical port; and an outer end provided with a cartridge receiving opening. The connector cartridge is sized and configured to be inserted in the cartridge receiving cavity. The connector cartridge has a cartridge inner end for facing the test instrument optical port when in use, and a cartridge outer end for receiving an optic fiber from a device under test (DUT). The connector cartridge houses a fiber optic cable extending between the cartridge inner end and the cartridge outer end. The connector cartridge is removably connectable to the instrument casing to allow replacement of the connector cartridge when the cartridge outer end is worn or damaged.

Abstract: This disclosure describes inputting pulsated pump light in a fundamental mode or a first higher-order mode into one end of an optical fiber under test constructed by connecting two optical fibers in series; inputting probe light having an optical frequency difference within a Brillouin frequency shift range with respect to the pump light into the other end of the optical fiber under test in the fundamental mode or the first higher-order mode; measuring a Brillouin gain distribution related to a distance of transmitted light intensity of probe light output from the one end into which the pump light was input; and calculating each inter-modal coupling efficiency at the connection point of the optical fiber under test.

Abstract: Methods for estimating the Effective Modal Bandwidth (EMB) of laser optimized Multimode Fiber (MMF) at a specified wavelength, ?S, based on the measured EMB at a first reference measurement wavelength, ?M. In these methods the Differential Mode Delay (DMD) of a MMF is measured and the Effective Modal Bandwidth (EMB) is computed at a first measurement wavelength. By extracting signal features such as centroids, peak power, pulse widths, and skews, as described in this disclosure, the EMB can be estimated at a second specified wavelength with different degrees of accuracy. The first method estimates the EMB at the second specified wavelength based on measurements at the reference wavelength. The second method predicts if the EMB at the second specified wavelength is equal or greater than a specified bandwidth limit.

Abstract: An isolator based on a waveguide-based artificial dielectric medium is scalable to a range of desired terahertz frequencies, has non-reciprocal transmission and provides low insertion loss and high isolation at various tunable terahertz frequencies, far exceeding the performance of other terahertz isolators, and rivaling that of commercial optical isolators based on the Faraday effect. This approach offers a promising new route for polarization control of free-space terahertz beams in various instrumentation applications. Artificial dielectrics are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. A simple and effective strategy implements a polarizing-beam-splitter and a quarter wave plate to form a highly effective isolator. Performance of the device is believed to exceed that of any other experimentally demonstrated method for isolation of back-reflections for terahertz beams.

Abstract: A hybrid automated testing equipment (ATE) system can simultaneously test electrical and optical components of a device under test, such as an optical transceiver. The device under test can be a multilane optical transceiver that transmits different channels of data on different lanes. The hybrid ATE system can include one or more light sources and optical switches in an optical test lane selector to selectively test and calibrate each optical and electrical components of each lane of the device under test.

Abstract: A wavelength checker includes an optical waveguide chip. A known arrayed-waveguide diffraction grating is formed on the optical waveguide chip. The wavelength checker includes a light conversion unit made of a conversion material that converts infrared light into visible light. The light conversion unit is arranged on an output side of a plurality of first output waveguides of the optical waveguide chip to be capable of receiving light emitted from the plurality of first output waveguides. The light conversion unit is formed on a side surface of a support facing an output end surface of the optical waveguide chip. The support is fixed to a main board.

Abstract: An optical testing circuit on a wafer includes an optical input configured to receive an optical test signal and photodetectors configured to generate corresponding electrical signals in response to optical processing of the optical test signal through the optical testing circuit. The electrical signals are simultaneously sensed by a probe circuit and then processed. In one process, test data from the electrical signals is simultaneously generated at each step of a sweep in wavelength of the optical test signal and output in response to a step change. In another process, the electrical signals are sequentially selected and the sweep in wavelength of the optical test signal is performed for each selected electrical signal to generate the test data.

Abstract: A scanning probe microscope including a holder having at least one electric port, wherein the holder is configured to support a sample to be imaged. The scanning probe microscope further includes a probe and an actuator configured to move at least one of the holder and the probe up to three directions. The scanning probe microscope further includes a reflectometer configured to measure reflection and/or transmission coefficients at each of the at least one electric ports of the holder by feeding each of the at least one electric ports of the holder with electromagnetic wave signals.

Abstract: The disclosed systems and methods for characterizing an optical fiber in a dense wavelength division multiplexing (DWDM) optical link. The characterizing comprising: i) applying a power dither to data bearing optical signals propagating in the optical fiber, the power dither having a high-power level and a low-power level; ii) computing optical time-domain reflectometer (OTDR) traces corresponding to the high-power level and the low-power level of the power dither; iii) averaging the OTDR traces corresponding to the high-power level and the OTDR traces corresponding to the low-power level into average OTDR traces; computing a differential Stimulated Raman Scattering (SRS) gain from the OTDR traces; and iv) adjusting the average OTDR traces based on the differential SRS gain.

Abstract: An optical cable includes an optical fiber having a fiber core and a fiber cladding, and an output coupling plug at an output coupling-side fiber end of the optical fiber. The output coupling plug comprises at least one cladding light sensor arranged behind the output coupling-side fiber end and configured to measure cladding light that exits frontally from the fiber cladding at the output coupling-side fiber end.

Abstract: An adjustable attenuation wrap plug for insertion into a signal port at an end product includes a housing with a protruding input prong and output prong, wherein a signal cable is coupled to the input prong and the output prong. The adjustable attenuation wrap plug further includes a ratchet mechanism at least partially disposed in the housing, wherein the ratchet mechanism is configurable to alter a shape of the signal cable.

Abstract: Embodiments of the present disclosure relate to a display apparatus. The display apparatus includes: a display; a user interface; and a controller, configured to perform: in response to a user input, synchronizing menu content data set under a current source to other sources, so that the other sources can obtain the same display effect as that under the current source. Unnecessary repeated setting is avoided, and convenience is brought to users in use.

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: A time of flight (TOF) assembly includes a laser light source, one or more photo detectors and a detection circuit. The one or more photo detectors are configured to receive light and convert the received light into an electric signal. The detection circuit is configured to send a turning-off control signal to turn off the laser light source in response to the electric signal indicating that a time length, in which the laser light source is in an effective working state within a first duration, is greater than a preset time length threshold value or the electric signal indicating that energy of light emitted from the laser light source within a second duration is greater than a preset energy threshold. The disclosure also provides a terminal device and a control method for a TOF assembly.

Abstract: In some examples, an optical time-domain reflectometer (OTDR)-based high reflective event measurement system may include an OTDR, and an N by M optical switch optically connected to the OTDR or disposed within the OTDR. The optical switch may include a variable attenuator mode and at least one optical fiber connected to at least one output port of the optical switch. At least one fiber optic reflector may be disposed at an end of the at least one optical fiber. A variable optical attenuator may reduce, for the at least one optical fiber including the at least one fiber optic reflector, an amplitude of reflective peaks.

Abstract: There is provided a method for measuring the PDL of a DUT as a function of the optical frequency ? within a spectral range, which uses a single wavelength scan over which the input-SOP varies in a continuous manner. The power transmission through the DUT, curve T(?), is measured during the scan and the PDL is derived from the sideband components of the power transmission curve T(?) that results from the continuously varying input-SOP. More specifically, the Discrete Fourier Transform (DFT) of the power transmission curve T(?) is calculated, wherein the DFT shows at least two sidebands. At least two sidebands are extracted and their inverse DFT calculated individually to obtain complex transmissions (?), =?J . . . J, where J is the number of sidebands on one side.

Abstract: Methods and systems for implementing a traditional computer vision algorithm as a neural network. The method includes: receiving a definition of the traditional computer vision algorithm that identifies a sequence of one or more traditional computer vision algorithm operations; mapping each of the one or more traditional computer vision algorithm operations to a set of one or more neural network primitives that is mathematically equivalent to that traditional computer vision algorithm operation; linking the one or more network primitives mapped to each traditional computer vision algorithm operation according to the sequence to form a neural network representing the traditional computer vision algorithm; and configuring hardware logic capable of implementing a neural network to implement the neural network that represents the traditional computer vision algorithm.

Abstract: In an optical fiber monitoring system which detects physical disturbance or other parameters such as temperature or strain of a fiber where a monitor signal is transmitted along the optical fiber and analyzed to detect changes which are indicative of an event, a method is provided for periodically checking proper operation of the optical fiber monitoring system. :A fiber disturbance actuator periodically causes a pattern of disturbances of a portion of the fiber at a predetermined location thereon where the disturbance is characteristic of the event to be monitored. The monitor signal is analyzed to detect the pattern of changes and in the event that expected changes are not detected, a warning is issued that the intrusion detection system is not properly operating.

Abstract: Systems and methods include a method for overcoming optical time domain reflectometry (OTDR) dead zone limitations by using a few-mode fiber (FMF). Optical pulses are transmitted by a transmitter of an OTDR system through a mode MUX/DEMUX into an FMF. Light signals directed by the FMF in a backward direction through the mode MUX/DEMUX are received by the OTDR system through N single-mode fiber (SMF) ports corresponding to N modes in the FMF. Light signals from N?1 dead-zone-free SMF ports are collected by the OTDR system. Losses are measured and faults are located in the FMF based at least on the light signals.

Abstract: An OSS foreshortening detection system employing an interventional device (40) including a OSS sensor (20) having shape nodes for generating shape sensing data informative of a shape of OSS sensor (20). The system further employs a OSS foreshortening detection device (80) including a OSS shape controller (90) for reconstructing a shape of a portion/entirety of interventional device (40) derived from a generation of the shape sensing data by OSS sensor (20). Device (80) further includes a OSS foreshortening controller (100) for monitoring any foreshortening of the interventional device (40) within an image of the interventional device (40) including the OSS foreshortening controller (100) detecting a location of any occurrence of a foreshortening of the interventional device (40) within the image of interventional device (40) derived from the reconstruction of the shape of the portion/entirety of interventional device (40) by the OSS shape controller (90).

Abstract: Channel predictive behavior and fault analysis may be provided. A forward time value may be determined comprising a time a forward signal takes to travel from a transmitter over a channel to the receiver. Next, a reflected time value may be determined comprising a time a reflected signal takes to travel to the receiver. The reflected signal may be associated with the forward signal. A discontinuity may then be determined to exist on the channel based on the forward time value and the reflected time value. The reflected signal may be caused by the discontinuity and a high impedance or low impedance at the transmitter present after the forward signal is sent.

Abstract: A method for fabricating an integrated structure, using a fabrication system having a CMOS line and a photonics line, includes the steps of: in the photonics line, fabricating a first photonics component in a silicon wafer; transferring the wafer from the photonics line to the CMOS line; and in the CMOS line, fabricating a CMOS component in the silicon wafer. Additionally, a monolithic integrated structure includes a silicon wafer with a waveguide and a CMOS component formed therein, wherein the waveguide structure includes a ridge extending away from the upper surface of the silicon wafer. A monolithic integrated structure is also provided which has a photonics component and a CMOS component formed therein, the photonics component including a waveguide having a width of 0.5 ?m to 13 ?m.

Abstract: An OVNA system employing an array of reference delays to estimate distance-variant phase distortion in probe light during an optical-frequency sweep thereof. The estimated distance-variant phase distortion is then used to perform a phase correction for the digital electrical signals generated in response to the probe light being passed through a device under test (DUT) during the same optical-frequency sweep. Advantageously, the performed phase correction enables the OVNA system to provide a more-accurate determination of certain optical characteristics of the DUT than that achievable without such phase correction.

Abstract: The disclosure relates to a method, an optical receiver and an optical system for compensating, at an optical receiver, signal distortions induced in an optical carrier signal by a periodic copropagating optical signal, wherein the optical carrier signal and the copropagating signal copropagate at least in part of an optical system or network, by: receiving, at the optical receiver, the optical carrier signal, wherein the optical carrier signal is distorted by the copropagating signal; determining, at the optical receiver, a period of a periodic component of the distorted optical carrier signal; determining, at the optical receiver, a periodic distortion of the distorted optical carrier signal; and generating a compensation signal to correct the distorted optical carrier signal according to the determined periodic distortion.

Abstract: Methods of measuring an anomaly, any induced change in physical parameters such as strain, temperature, and so forth, in an optical fiber. One method may include launching a plurality of probe pulses from a probe source; recording a Brillouin scattering spectrum from a plurality of reflection signals generated in the optical fiber, responsive to the plurality of probe pulses; determining a relative motion between the optical fiber and the anomaly during the recording the Brillouin back-scattering spectrum; and dynamically adjusting the Brillouin back-scattering spectrum according to the relative motion, or performing an adjustment of the Brillouin back-scattering spectrum after acquisition of the Brillouin back-scattering spectrum.

Abstract: A photon source module includes a plurality of photon sources, wherein each photon source is configured to non-deterministically generate one or more non-entangled or entangled photons in response to receiving a trigger signal. When two or more photon sources simultaneously generate photons in response to a trigger signal, one photon of a first photon pair is directed to a photon processing system and one photon of a second photon pair is directed to a photon analyzer. During repetitive operation, the photon analyzer analyzes photons from each of the plurality of photon sources to determine characteristics of each photon source and can use that information to direct the highest quality photons to the photon processing system.