Abstract: Raman amplifier systems and methods with an integrated Optical Time Domain Reflectometer (OTDR) for integrated testing functionality include an amplifier system, an OTDR and telemetry subsystem, and a method of operation. The OTDR and telemetry subsystem is configured to operate in an OTDR mode when coupled to a line in port and to operate in a telemetry mode when coupled to a line out port. The OTDR and telemetry subsystem enables on-demand fiber testing while also operating as a telemetry channel that is both a redundant optical service channel (OSC) and provides a mechanism to monitor Raman gain over time. The OTDR and telemetry subsystem minimizes cost and space by sharing major optical and electrical components between the integrated OTDR and other functions on the Raman amplifier.

Abstract: There are proposed an optical fiber property measuring device and an optical fiber property measuring method which can enhance spatial resolution more than before. In the present invention, in synchronization with frequency modulation applied to x-polarized light, intensity modulation is also applied to the x-polarized light by an intensity modulation means. This makes it possible to increase or decrease the intensity of the x-polarized light at a specific frequency, thereby allowing the effective length of a Brillouin dynamic grating formed by the x-polarized light to be adjusted. As a result, the shape of the reflection spectrum obtained when y-polarized light is reflecting by the Brillouin dynamic grating can also be adjusted optimally, which leads to enhancement of spatial resolution with the y-polarized light.

Abstract: Methods and systems for sensing conditions of a fiber include splitting a light signal into two branches. A first branch is converted to have a mode different from that of the second branch. Both branches are mode multiplexed into a single fiber. An output of the fiber is mode demultiplexed into the two branches. The first branch is mode converted to its original mode. Brillouin scattering patterns of the two branches are compared to determine a temperature and strain profile of the fiber.

Abstract: A fiber link recognition method, device, and system, to recognize different fiber links where the method includes sending, by a link recognition device, a first test optical signal, receiving a second test optical signal that is returned after the first test optical signal is sent to a connection port of a first optical node, acquiring a reflection peak of the second test optical signal on a fiber link, determining a port identifier of the connection port of the first optical node according to the reflection peak of the second test optical signal on the fiber link, and recognizing, the fiber link corresponding to the second test optical signal that is returned by the connection port of the first optical node. The method embodiment is used to recognize a fiber link.

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: According to embodiments of the present disclosure, an apparatus for adjusting the luminance of a screen of a spliced display device may include: an adjustment module configured to control rotation of a light-emitting unit within a backlight module in the spliced display device within a range; a collection module configured to collect a plurality of pieces of luminance information of a spliced screen of the spliced display device when the light-emitting unit is rotated at various angles; and a processing module configured to calculate a ratio between a minimum luminance value and a maximum luminance value for each piece of the luminance information, determine a maximum value among a plurality of the ratios and a specific angle of rotation of the light-emitting unit corresponding to the luminance information having the maximum value, and rotate the light-emitting unit at the specific angle of rotation by controlling the adjustment module.

Abstract: Embodiments of the present invention disclose a method, an apparatus, and a system for detecting an optical network. The method comprises: receiving, by a management device, a reflection peak power reported by a testing device, where the reflection peak power is a reflection peak power of an optical splitter that is obtained by the testing device according to a reflected optical signal, the reflected optical signal is an optical signal obtained by reflecting, by the optical splitter, a testing optical signal that is sent by the testing device and is transmitted to the optical splitter through an optical cable, and the optical splitter reflects the testing optical signal by using a reflective film disposed on an end surface of one optical output port. a detector does not need to carry a testing device to a site, to perform detection, efficiency of detecting performance of an optical network is improved.

Abstract: A method for reviewing a defect including a light capturing step that illuminates a sample with light under plural optical conditions, while varying only at least one of illumination conditions, sample conditions, or detection conditions, and detects plural lights scattering from the sample; a signal obtaining step that obtains plural signals based on the lights detected; and a processing step that discriminates a defect from noise according to a waveform characteristic quantity, an image characteristic quantity, or a value characteristic quantity created using the signals and derives the coordinates of defect.

Abstract: To eliminate a need for polarization adjustment, to simplify a configuration, and to make a configuration at low cost. Wavelength swept light is provided to a measurement-target optical fiber having an FBG with a chirped grating interval. A polarization multiplexing unit generates polarization multiplexed reference light by multiplexing first reference light and second reference light, which are swept in a wavelength in the same manner as wavelength swept light and have polarizations orthogonal to each other. Polarization multiplexed reference light is input to combine means along with reflected light from measurement-target optical fiber and is made to interfere with reflected light. A signal processing unit performs Fourier transform processing on the digital signal by dividing a time domain into a plurality of periods, and synthesizes the Fourier transform results on a distance axis to obtain a measurement result of orthogonal polarization components of reflected light.

Abstract: The reflectometric method for measuring an optical loss value of an optical fiber link generally comprises: obtaining at least one bias value being indicative of a bias induced by differing backscattering characteristics of a first optical fiber length and a second optical fiber length; propagating at least one test signal serially into the first optical fiber length, the optical fiber link and the second optical fiber length; monitoring at least one return signal resulting respectively from the propagation of the at least one test signal; and determining the optical loss value based on the at least one return signal and the at least one bias value.

Abstract: A method and apparatus for approaches for troubleshooting optical networks, particularly ROADM-based networks is described. The method includes designating a first port, of an optical communication node of a transport network, as an ingress for a loop-back optical signal to troubleshoot the transport network, designating a second port, of the optical communication node, as an egress for the loop-back optical signal, and establishing a loop-back connection between the first port and the second port to transport the loop-back optical signal.

Abstract: A method of validating connections in an optical add/drop multiplexer (OADM) that includes a plurality of modules configured to route optical signals through the OADM, and at least one multi-fiber cable connecting modules of the OADM. A light source coupled to a first port of a first module is controlled to emit a test light. A determination is made whether or not the test light is received at a first photo-detector connected to a second port. Continuity of a connection between the first port and the second port is validated when the test light is received at the first photo-detector.

Abstract: Systems, methods, and devices are disclosed for monitoring optical communications between a managed location and a remote location. In particular, an optical signal is transmitted over an optical fiber and passed-through a test device. A portion of the optical signal is filtered from the original optical signal and passed to a monitoring unit. The monitoring unit may instruct one or more switches in the test device to loop the optical signal back toward the managed location. Subsequently, testing and monitoring may be performed at the managed location. The device may provide a test output or may transmit the information to the managed location.

Abstract: An apparatus includes: a first measurer configured to measure first phase data indicating a temporal variation in a phase of a non-transferred signal that is an optical signal modulated by an optical phase modulation scheme and output from a transmitting device to an optical transmission path as the non-transferred signal; a second measurer configured to second phase data indicating a temporal variation in the phase of the optical signal transferred by the optical transmission path as a transferred signal on a side of a receiving device; a generator configured to generate differential data indicating a difference between the first phase data and the second phase data; and an extractor configured to use the differential data to extract, from the optical signal on the side of the receiving device, optical phase noise generated due to the optical transmission path.

Abstract: An optical receiver includes a dividing unit, a control unit, and a compensating unit. The dividing unit divides an optical transmission signal into a plurality of frequency components by a set number of divisions and a set division bandwidth. The control unit controls the number of divisions and the division bandwidth on the basis of transmission path information about an optical transmission line through which the optical transmission signal is transmitted and signal information about the optical transmission signal. The compensating unit compensates optical nonlinear distortion of each of the frequency components divided by the dividing unit.

Abstract: A portable apparatus for measuring optical powers of optical signals propagating concurrently in opposite directions in an optical transmission path between two elements, at least one of the elements being operative to transmit a first optical signal (S1) only if it continues to receive a second optical signal (S2) from the other of said elements, comprises first and second connector means for connecting the apparatus into the optical transmission path in series therewith, and propagating and measuring means connected between the first and second connector means for propagating at least the second optical signal (S2) towards the one of the elements, and measuring the optical powers of the concurrently propagating optical signals (S1, S2). The measurement results may be displayed by a suitable display unit. Where one element transmits signals at two different wavelengths, the apparatus may separate parts of the corresponding optical signal portion according to wavelength and process them separately.

Abstract: System and method for correcting the potential errors occurring in a fiber optic temperature measurement system are disclosed. In one respect, a dual light sources configuration is provided. The primary light source may illuminate a sensing fiber, and an Anti-Stokes band may be detected. The secondary light source may illuminate a sensing fiber, and a Rayleigh band may be detected, where the Rayleigh band is substantially wide enough to cover the Anti-Stokes band of the primary light source. A ratio between these Anti-Stokes and the Rayleigh bands may be used to measure the temperature and undesired errors due to the perturbations falling on the sensing fiber is continuously corrected.

Abstract: A safe-mode OTDR method for characterizing an optical fiber link is provided, as well as an OTDR apparatus operating under such a safe mode. The method includes performing OTDR acquisitions along the fiber link using an OTDR apparatus connected at a proximal end of the optical fiber link, and operating under OTDR acquisition conditions that have been deemed safe for a communication device at a distal end of the fiber link. The obtained reflectometric trace, representing a proximal portion of the optical fiber link, is used to determine a partial-link loss value associated with the proximal portion of the fiber link. Modified acquisition conditions that are safe for the communication device are determined based on the partial-link loss value and on loss-related maximum rating parameters for the communication device. The process is repeated using the modified OTDR acquisition conditions until the end of the link has been reached.

Abstract: A distributed Raman amplifier system is disclosed. Distributed Raman amplifier systems can include a spool of fiber disposed between a distributed Raman amplifier and local or proximate optical point-loss sources, a carrier hotel for example. The spool of fiber has a fiber of sufficient length to offset aggregated losses, which prevents the distributed Raman amplifier from shutting down while also allowing the distributed Raman amplifier to achieve entitled gain by pumping the fiber in the spool.

Abstract: Techniques for determining lateral offset of the source of an acoustic disturbance in a distributed acoustic fiber optic sensor are described. The sensor comprises an optical source (112) for interrogating an optical fiber (104) and a detector (116) and processor (108) arranged to detect any backscattered radiation and determine a measurement signal for a plurality of discrete longitudinal sensing portions of the optical fiber. The processor is also arranged to analyse the measurement signals to identify signals corresponding to the same acoustic wave arriving at different parts of the fiber and determine from the time of arrival of said acoustic wave the direction and/or distance of the origin of said acoustic wave from the optical fiber. The geometry of the fiber may be arranged to ensure that any positional ambiguity can be resolved and the use of multiple fibers (501, 502) is disclosed.

Abstract: The disclosed technology in this patent document includes, among others, methods apparatus for distributed measuring at least one fiber bend or stress related characteristics along an optical path of fiber under test (FUT) uses both a light input unit and a light output unit connected to the FUT at one single end.

Abstract: A wide-band optical frequency comb is provided to estimate an optical phase shift induced in a dispersive material. In contrast to the conventional techniques that rely on a single tunable laser for extracting the dispersion parameter at different frequencies, the wide-band optical frequency comb uses multiple comb lines for simultaneously evaluating the dispersion induced phase shifts in different frequencies. Since the frequency response of the dispersive material is a phase function, a phase associated with each comb line passed through the material represents a discrete measure of the material frequency response.

Abstract: The present invention relates to a distributed sensing optical fiber performance multi-objective multi-degree-of-freedom static and dynamic test integrated platform and a test method. Wherein an optical fiber multi-degree-of-freedom fixing system is sequentially connected with an artificial loading and unloading device and an oil pressure control loading and unloading device, and an optical fiber under test is connected with the optical fiber multi-degree-of-freedom fixing system and a distributed optical fiber Brillouin frequency shift acquisition system; and test on performance of optical fiber is achieved by controlling devices in the optical fiber multi-degree-of-freedom fixing system. The device of the present invention has a large number of advantages such as a simple structure, a low cost, convenient operation, less disturbance, many test classes, strong adaptability, stable performance and convenient loading and unloading.

Abstract: A spectroscopic analysis device based on Brillouin dynamic grating and its analysis method, which provides high resolution and large measuring range at the same time. The device includes a laser device (1), a fiber optic coupler device (2), a first fiber amplifier device (3), a first isolator (4), a first polarization controller (5), a second polarization controller (6), a single-sideband modulation modulator (7), a second fiber amplifier device (8), a second isolator (9), a third polarization controller (10), a single-mode fiber (11), a polarization beam splitter (12), a circulator (13), a photodetector (14), a data acquisition card (15), a fourth polarization controller (16) and a microwave source (17). The method utilizes the Brillouin scattering of two beams of pump light in optical fiber forming Brillouin dynamic gratings as the spectral element and achieve a sub-MHz resolution.

Abstract: An optical coherence analysis system comprising: a first swept source that generates a first optical signal that is tuned over a first spectral scan band, a second swept source that generates a second optical signal that is tuned over a second spectral scan band, a combiner for combining the first optical signal and the second optical signal to form a combined optical signal, an interferometer for dividing the combined optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample, and a detector system for detecting an interference signal generated from the combined optical signal from the reference arm and from the sample arm.

Abstract: Systems and apparatus for a wirelessly-powered passive optical power meter device. In one aspect, an optical power meter device comprises a power circuit connected to one or more antennas, the circuit including an RF to DC converter that generates a DC power signal that provides a DC power source for the optical power meter from an RF signal received by the one or more antennas, a photodetector that generates a power measurement signal that measures the power of the optical input signal, and a communication circuit that is connected to the one or more antennas, the photodetector, and the power circuit that when powered by the DC power source generates a modulation signal that is responsive to the power measurement signal and that causes the one of the one or more antennas to convey the power measurement signal to a reader device that is transmitting the RF signal.

Abstract: An OTDR device and method for characterizing one or more events in an optical fiber link are provided. A plurality of light acquisitions is performed. For each light acquisition, test light pulses are propagated in the optical fiber link and the corresponding return light signals from the optical fiber link are detected. The light acquisitions are performed under different acquisition conditions, for example using different pulsewidths or wavelengths. Parameters characterizing the event are derived using the detected return signal from at least two of the plurality of light acquisitions.

Abstract: A measuring method of a longitudinal distribution of bending loss of an optical fiber includes calculating an arithmetical mean value I(x) from two backscattering light intensities of two backscattering light at a position x obtained by bidirectional OTDR measurement of the optical fiber; and obtaining a bending loss value at the position x from a mode field diameter 2W(x) and a relative refractive index difference ?(x) at the position x calculated from the arithmetical mean value.

Abstract: There is provided a photonic bandgap fiber used in a state in which at least a part of the photonic bandgap fiber is bent at radii of 15 cm or greater and 25 cm or less. A large number of high refractive index portions 57 are disposed in a nineteen-cell core type in three layers, and a V value is 1.5 or greater and 1.63 or less. In the high refractive index portions 57, conditions are defined that a relative refractive index difference is ?% and a lattice constant is ? ?m so as to remove light in a higher mode at the bent portion as described above.

Abstract: Checking continuity along an optical fiber includes mounting an inspection attachment member to a smart phone; inserting a first end of the optical fiber into a receiving arrangement of the inspection attachment member to align the first end with a light source of the smart phone; activating the light source of the smart phone to shine a light along the optical fiber; and determining whether the light is visible at an opposite end of the optical fiber. Certain types of inspection attachment members also are configured to align an end of an optical fiber with a camera lens of the smart phone.

Abstract: A scanning sensor system, methods of use and kits for detecting a biologically active analyte are provided. The scanning senor system includes a light source, a detector, a substrate comprising a plurality of waveguides and a plurality of optical sensing sites in optical communication with one or more waveguide of the substrate, and at least one adapter configured to couple with the substrate and provide optical communication between the light source, the waveguides of the substrate, and the detector.

Abstract: Apparatus and method of simultaneously measuring a parameter of a plurality of cores in at least one optical fiber. An input tester at a first end of the test fiber has a plurality of tester signal inputs with a geometry substantially matching at least a portion of the core geometry of the fiber. At least one test input signal source coupled to the plurality of tester signal inputs. A signal measuring device is alignable at a second end of the fiber to measure the output of the test input signal. The input tester may include a tapered multicore coupler or a laser having a shield with apertures disposable between the laser and the fiber. In the latter case, a lens may be disposed between the shield and the fiber to project light from the laser that passes through the apertures onto the end of the fiber.

Abstract: An optical fiber flexible multi-wavelength filter based on a polarization-diversity loop includes a pair of high-birefringence optical fibers, a polarization beam splitter connected to the pair of high-birefringence optical fibers and dividing light incident from a broadband light source into two polarized beams, and a polarization controller connected to the high-birefringence optical fibers or the polarization beam splitter and controlling the two polarized beams divided by the polarization beam splitter. The polarization controller includes a ½ wave plate or a ¼ wave plate, and the polarization controller disposed between the high-birefringence optical fibers controls an angle difference between principal axes of the high-birefringence optical fibers and visibility. Interference in the high-birefringence optical fibers is controlled via changing polarized light incident from the broadband light source using the polarization controller.

Abstract: A Kerr medium is introduced into OFDR configuration to enable phase to power variation conversion thereby enabling an all-optical beat signal acquisition, thus eliminating performance limits associated with bandwidth capabilities of electronic and optoelectronic components.

Abstract: The present disclosure provides dynamic performance monitoring systems and methods for optical networks to ascertain optical network health in a flexible and accurate manner. The present invention introduces accurate estimations for optical channel performance characteristics based either on existing channels or with a dynamic optical probe configured to measure characteristics on unequipped wavelengths. Advantageously, the dynamic performance monitoring systems and methods introduce the ability to determine physical layer viability in addition to logical layer viability.

Abstract: A diagnostic module may include an inspection device, a cleaning device, and in various other examples, a verification device. The inspection device may inspect an optical fiber end-face of an optical fiber. The cleaning device may clean the optical fiber end-face of the optical fiber. The diagnostic module may automatically move from an optical connector to another optical connector.

Abstract: A method for testing the operation of an optical fiber cable in a communication network using an optical loss test set (OLTS) instrument includes receiving a range of identifiers of fibers to be tested. Identifiers of a first fiber set to be tested are displayed. The first fiber set comprises one or more fibers. The first fiber pair is included in the range. The first fiber pair is a next fiber pair to be tested. A determination is made whether the first fiber set is connected to the OLTS instrument. In response to determining that the first fiber set is connected to the OLTS instrument, a test of the first fiber set operation is performed using the OLTS instrument. Identifiers of a second fiber set are displayed. The second fiber set is included in the range and constitutes a next fiber set to be tested.

Abstract: An optical communication system includes a transmission apparatus that transmits a test signal over an optical communication medium using a first optical modulation format, receives a reception report for the test signal, determines, based on the received reception report, a pre-equalization scheme, applies the pre-equalization to data transmitted from the transmitter side to generate pre-equalized data and transmits the pre-equalized data using a second optical modulation format based on the reception report. An optical reception apparatus receives the test signal, computes a channel transfer function based on the received test signal, and transmits the reception report.

Abstract: A system and method of validating a connection to an optical circuit switch include sending a packet of data through a first connection to the optical circuit switch to test whether the packet reaches a second connection to the optical circuit switch. The first connection may be selected for retesting with a third connection and a second packet of data may be sent to the third connection. Data indicative of the first connection being correctly wired may be generated based in part on a determination that the second packet reached the third connection.

Abstract: A testing system and method are provided. The testing system includes a terminal device (Optical Line Terminal, OLT) which is configured to provide an optical signal, an optical attenuator which is configured to generate an attenuation optical signal according to the optical signal, a tested device which is configured to generate an analog-to-digital (AD) value corresponding to the attenuation optical signal, and a test-managing device which is configured to receive the analog-to-digital (AD) value and generate calibration values according to the analog-to-digital (AD) value and the attenuation optical signal and transmit the calibration values to the tested device to test the tested device.

Abstract: Optical coherence tomography (OCT) is an imaging method which can image with micrometer-scale resolution up to a few millimeters deep into, for example, living biological tissues and preserved tissue samples. An improved apparatus and image reconstruction algorithm for parallel Fourier Domain OCT which greatly eases requirements for interferometer stability and also allows for more efficient parallel image acquisition is provided. The apparatuses and algorithms reconstruct images from interfered, low-coherence, multiwave length signals having a .pi. radian phase difference relative to one another. Other numbers of signals and other phase differences may be alternatively used, with some combinations resulting in higher resolution and image stability. The apparatus also eliminates a need for bulk optics to modulate a phase delay in a reference arm of the optical path. Images may be reconstructed using two spectrometers, where each is coupled to a detector array such as a photodiode array.

Abstract: A system for creating an optical time domain reflectometer (OTDR) in a small package is described. This system allows the implementation of multiple channels of OTDR in package of similar size to existing fiber optic transceivers.

Abstract: A method for measuring Brillouin backscattering from an optical fiber, comprising mixing backscattered light received from the optical fiber and having a Brillouin frequency f?(t) with coherent light at a frequency f i in an optical detector to produce an electrical signal with a difference frequency ?F(t)=f?(t)?f15 and directly digitizing the electrical signal using an analog-to-digital converter to generate a sequence of samples representing the electrical signal, the samples then being processed to determine one or more properties of the Brillouin spectral line. The difference frequency may be further reduced by an additional frequency mixing stage to allow digitization at a lower sampling rate.

Abstract: There is provided an optical reflectometric method and system for characterizing an optical fiber link, wherein events in the fiber optic link under test are identified and values of parameters characterizing the events (e.g. location, insertion loss and reflectance) are extracted from an analysis of one or more reflectometric measurements performed on the optical fiber link. A loss profile and/or a reflectance profile are then constructed. The loss and reflectance profiles are typically displayed on screen or otherwise graphically represented for an operator to be able to appreciate the measurement results at a single glance.

Abstract: A method of analysing performance of an optical fiber link. As a preliminary step, a reference trace indicative of a distributed optical performance of the optical fiber link is derived. During in-service operation of the optical fiber link, an Optical Time Domain Reflectometry (OTDR) sub-system measures an OTDR trace with Raman amplification ON, and a real-time cumulative Raman Gain profile of the optical fiber link is calculated based on the reference trace and the measured OTDR trace.

Abstract: A compact spectrometer is disclosed that is suitable for use in mobile devices such as cellular telephones. In preferred embodiments, the spectrometer comprises a filter, at least one Fourier transform focusing element, a micro-lens array, and a detector, but does not use any dispersive elements. Methods for using the spectrometer as an end-user device for performing on-site determinations of food quality, in particular, by comparison with an updatable database accessible by all users of the device, are also disclosed.

Abstract: Methods and apparatus for measuring the modal bandwidth of a multimode optical fiber as a function of wavelength are disclosed. The methods include emitting polarized light from a single-mode fiber, frequency-modulating the single-mode polarized light, and then conditioning the frequency-modulated polarized light to excite multiple modes of the multimode optical fiber. The multimode light transmitted by the multimode optical fiber is detected and analyzed by a network analyzer to determine a bandwidth for at least three different wavelengths. A controller performs a fit to the measured bandwidths using a fitting equation to determine the modal bandwidth as a function of wavelength.

Abstract: A multicore fiber alignment apparatus is described, having a chassis into which is mounted ferrule-holding means for holding a multicore fiber ferrule having one or more capillaries extending therethrough. Fiber-holding means for holding one or more multicore fibers in position to be mounted into the ferrule, such that each multicore fiber extends through a respective ferrule capillary. Means are provided for monitoring the rotation angle of each multicore fiber within its respective capillary, relative to a reference rotational orientation. Means are further provided for rotating each of the multicore fibers within its respective capillary. The rotational orientation of each multicore fiber is fixed when its rotation angle is equal to zero.

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: Under a known pressure is externally applied to a reference member to which an optical fiber is fixed, test light is allowed to enter the optical fiber, and at least one of a reference Brillouin measurement for determining a reference Brillouin frequency shift amount based on the Brillouin scattering phenomenon, and a reference Rayleigh measurement for determining a reference Rayleigh frequency shift amount based on the Rayleigh scattering phenomenon is performed. A Brillouin measurement coefficient or a Rayleigh measurement coefficient is determined from these calculation results. An optical fiber is fixed to a sample member, the volumetric change of which is unknown, and the same sample Brillouin measurement or sample Rayleigh measurement is performed to determine the frequency shift amount. The volumetric change of the sample member is determined from the sample Brillouin or the sample Rayleigh frequency shift amount, and from the Brillouin or the Rayleigh measurement coefficient.