Abstract: The invention refers to an optical device for heterodyne interferometry, comprising a chip, a beam splitter, a first waveguide arranged on the chip, light propagating in the first waveguide being guided to the beam splitter, a second waveguide arranged on the chip, light propagating in the second waveguide being guided to and/or from the beam splitter, wherein the beam splitter, the first waveguide, and the second waveguide form part of a Michelson interferometer, wherein the first waveguide and the second waveguide at least partially form two arms of the Michelson interferometer, and wherein two further arms of the Michelson interferometer are at least partially arranged outside the chip.

Abstract: An integrated optical transducer for measuring displacement of a diaphragm comprises the diaphragm, a lens element and a substrate body having a waveguide structure and a coupling element. The diaphragm is arranged distant from the substrate body and substantially parallel to a main extension plane of the substrate body. The waveguide structure is configured to guide light from a light source to the coupling element and from the coupling element to a photodetector. The coupling element is configured to couple at least part of the light in the waveguide structure onto a light path between the coupling element and the diaphragm and to couple light reflected by a surface of the diaphragm from the light path into the waveguide structure. The lens element is arranged on the light path such that light on the light path passes through the lens element.

Abstract: A device for combining at least two input laser beams having different spectral components. At least one pre-compensation unit for the at least two input laser beams has a diffractive optical unit which expands the input laser beam into an intermediate beam bundle in which the spectral components are spatially arranged so as to be adjacent to one another with increasing wavelength. A combination unit has at least a first diffractive optical element and a second diffractive optical element, the combination unit being aligned with the pre-compensation unit in such a way that the first diffractive optical element converts an intermediate beam bundle into a convergent beam bundle having a beam waist, the beam waist lying on the second diffractive element, and the second diffractive optical element being designed in this way that all incident spectral components are diffracted in a common radiation direction.

Abstract: An optical system can include a mirror that reflects incoming light to a sensor for detection. The position and/or orientation of the mirror can be controlled to reflect incoming light from different locations and/or directions. Position and/or orientation of the mirror may be tracked and/or detected by an optical position sensor. The position sensor can transmit a beam to a reflector on the mirror, and the reflected beam can be received by the position sensor. Characteristics of the reflected beam can be measured to determine the position and/or orientation of the mirror. For example, the beam can be used for interferometric and/or intensity measurements, which can then be correlated with a position and/or orientation of the mirror.

Abstract: A method and apparatus for determining properties of a tissue or tissues imaged by optical coherence tomography (OCT). In one embodiment the backscatter and attenuation of the OCT optical beam is measured and based on these measurements and indicium such as color is assigned for each portion of the image corresponding to the specific value of the backscatter and attenuation for that portion. The image is then displayed with the indicia and a user can then determine the tissue characteristics. In an alternative embodiment the tissue characteristics is classified automatically by a program given the combination of backscatter and attenuation values.

Abstract: An optoelectronic sensor, including a transmitting unit for transmitting a plurality of optical signals in each case to a plurality of segments of an object, and a receiving unit that includes a first multichannel analog-digital converter device, including: an analog-digital converter unit; a plurality of signal processing channels, the signal processing channels of the plurality of signal processing channels in each case including: a detection antenna for receiving optical signals; and a modulator for generating an individual signal encoding. Signals of the plurality of signal processing channels, with individual signal encoding, are transmittable together to the analog-digital converter unit, are converted, and may be associated once again with the corresponding signal processing channels due to the individual signal encoding via algorithms.

Abstract: The LIDAR chip includes a utility waveguide that guides an outgoing LIDAR signal to a facet through which the outgoing LIDAR signal exits from the chip. The chip also includes a control branch that removes a portion of the outgoing LIDAR signal from the utility waveguide. The control branch includes a control light sensor that receives a light signal that includes light from the removed portion of the outgoing LIDAR signal. The chip also includes a data branch that removes a second portion of the outgoing LIDAR signal from the utility waveguide. The data branch includes a light-combining component that combines a reference light signal that includes light from the second portion of the outgoing LIDAR signal with a comparative light signal that includes light that was reflected off an object located off of the chip.

Abstract: An Optical Coherence Tomography receiver may include prisms, polarizing beam splitters, reflectors, lenses, and a photodetector array arranged in a compact package. Sample and reference beams are combined into an interference beam and split in two. The two resulting interference beams are then split into two polarization sates each. The optical path lengths for both pairs of interference beams with the same polarization state are equal or nearly equal.

Abstract: Translations of an object in a plurality of different spatial directions are measured using a plurality of interferometers to detect interference with light that has been reflected from a diffusively reflective surface, preferably using diffuse reflection from the same planar surface to measure in each of the different spatial directions. At least the interferometers that measure translation in directions that are not perpendicular to the surface each comprises a single mode fiber and a collimator configured to transmit the outgoing light to the object successively through the single mode fiber and the collimator, and to collect reflection into the single mode fiber with the collimator both along a same beam direction. It has been found that, when reflection of a beam with a beam direction at an oblique angle to a diffusively reflective surface is used, the interference resulting from translation of the object is due substantially only to translation in the beam direction.

Abstract: An integrated device includes a laser ranging module, a dual-branched fiber bundle, a beam splitter, and an image receiving module. The laser ranging module includes a light source, an optical receiver and a computing unit. The fiber bundle is disposed between the laser ranging module and the beam splitter. A target reflects a measuring beam emitted by the light source to form a reflected beam. The beam splitter splits the reflected beam into a first reflected beam and a second reflected beam. The first reflected beam is transmitted to the optical receiver through the fiber bundle to generate a measurement signal. The computing unit receives the measurement signal to calculate a distance between the target and the fiber bundle. The image receiving module is disposed on the optical path of the second reflected beam to receive the second reflected beam and displays the image of the target.

Abstract: A system for determination of intraocular pressure includes: an intraocular pressure sensor; a light source illuminating the sensor with one or more wavelengths of light; and a detector that measures emitted light from the sensor. The sensor includes a substrate member, a spacer member, and a flexible membrane, which define a sealed cavity. The flexible membrane moves in response to intraocular pressure changes. A device for measuring intraocular pressure includes: the sensor; an anchoring member attached to the sensor for immobilizing the sensor in an eye; and a protective member attached to the anchoring member and covering the sensor to prevent contact between the flexible membrane and the eye. A method for determination of intraocular pressure includes: placing the sensor in an eye; illuminating, with a light source, the sensor with one or more wavelengths of light; and detecting, with a detector, a resultant light that contains information about intraocular pressure.

Abstract: An interferometry system includes a plurality of coherent light sources that each generate a beam of coherent light. Separate waveguide pathways are optically associated with each coherent light source. Each separate waveguide pathway has an endpoint configured to emit at least a portion of the beam of coherent light from the associated light source. A plurality of photodetectors is optically associated with waveguide pathways. In some cases, a retroreflector receives the light emitted from the endpoints, modulates the received light, and directs the modulated light back to the endpoints. The modulated light and a portion of the coherent light reflected from the endpoint of the waveguide pathway receiving the modulated light is directed a photodetector.

Abstract: A composite substrate for an electro-optic element is disclosed. The composite substrate includes: an electro-optic crystal substrate having an electro-optic effect; a low-refractive-index layer being in contact with the electro-optic crystal substrate and having a lower refractive index than the electro-optical crystal substrate; and a support substrate bonded to the low-refractive-index layer at least via a bonding layer. A plurality of interfaces located between the low-refractive-index layer and the support substrate includes at least one rough interface having a roughness that is larger than a roughness of an interface between the electro-optic crystal substrate and the low-refractive-index layer.

Abstract: Devices, systems, and methods for determining a distance between at least two points are disclosed and described, wherein interferometry technology is utilized to determine such distances.

Abstract: A method, system and computer program product are provided for position and orientation measurement using a camera system having an optical boresight centerline. Methods may include: receiving at an aperture a collimated input beam; splitting the input beam at a first surface including a beam splitter into a first sub-beam and a second sub-beam; receiving at a first sensor the first sub-beam; receiving at a second sensor the second sub-beam; and determining one or more offsets of the input beam from the centerline based on data received from the first sensor and the second sensor. Methods may include: determining a location and irradiance of the first sub-beam of the input beam received by the first sensor; and determining a location and irradiance of the second sub-beam of the input beam received by the second sensor.

Abstract: The present disclosure provides a method of measuring a path length using a handheld electronic device comprising an acceleration sensor. The method comprises: sensing an acceleration of the handheld electronic device while the handheld electronic device is translated over the path, thereby obtaining an acceleration plot of the handheld device; and calculating the path length from the acceleration plot using an integration procedure. In some cases projection of a distance over a required measured path is used.

Abstract: A high-precision fiber Bragg grating dislocation sensor, including a fiber Bragg grating, a loose tube, a tension spring, a sliding rod, a positioning piece, a sheath, a stainless steel tube, a transmission rod and a fastener. The sliding rod, the tension spring, the positioning piece, the fiber Bragg grating and the sheath are connected in series, and are provided in the precision stainless steel tube successively. The mechanism of the dislocation sensor is that an elastic force, converted from the local uneven settlement of the settlement joint, is applied on the bare fiber Bragg grating, so that the bare fiber Bragg grating suffers an axial stress and a strain is generated by itself, and the central wavelength of the fiber Bragg grating is further changed, allowing for the monitoring of settlement.

Abstract: A photonic integrated circuit including a beam launching waveguide, a local oscillator waveguide, a target interferometer, and a reference interferometer all integrated on a chip. The beam launching waveguide transmits target electromagnetic radiation off the chip and receives a retroreflection of the target electromagnetic radiation from a target off the chip. The target interferometer interferes the retroreflection with a local oscillator field transmitted from the local oscillator waveguide so as to form a target interference signal. The reference interferometer interferes a portion of the target electromagnetic radiation that does not leave the chip with the local oscillator field transmitted from the local oscillator waveguide to form a reference interference signal. The difference between the reference interference signal and the target interference signal is used to measure a distance to the target from the chip.

Abstract: A method uses a two-dimensional (2D) camera in two different positions to provide first and second 2D images having three common cardinal points. It further uses a three-dimensional (3D) measuring device to measure two 3D coordinates. The first and second 2D images and the two 3D coordinates are combined to obtain a scaled 3D image.

Abstract: A method of forming a build in a powder bed includes emitting a plurality of laser beams from selected vertical-cavity surface emitting lasers (VCSELs) of at least one VCSEL array onto the powder bed, the selected VCSELs of the at least one VCSEL array corresponding to a pattern of a layer of the build; and simultaneously melting powder in the powder bed corresponding to the pattern of the layer of the build.

Abstract: A grating measuring device includes: a light source module (300) for generating two light beams having different frequencies, one of which serves as a measuring beam and the other as a reference beam; a grating (200); and a grating measuring probe (100) including a dual-frequency light reception module, a vertical measurement module, a vertical detection module and a reference detection module. The dual-frequency light reception module is configured to receive the measuring and reference beams, and the vertical measurement module is adapted to project the measuring beam onto the grating (200), collect a zeroth-order diffracted beam resulting from double diffraction occurring at the grating, and feed the zeroth-order diffracted beam to the vertical detection module. The zeroth-order diffracted beam interferes with the reference beam in the vertical detection module, resulting in a vertical interference signal.

Abstract: A phase-resolved heterodyne shearing interferometer has been developed for high-rate, whole field observations of transient surface motion. The sensor utilizes polarization multiplexing and multiple carrier frequencies to separate each segment of a shearing Mach-Zehnder interferometer. Post-processing routines have been developed to recombine the segments by extracting the scattered object phase from Doppler shifted intermediate carrier frequencies, providing quantitative relative phase changes and information to create variable shear, phase resolved shearographic fringe patterns without temporal or spatial phase shifting.

Abstract: When measurement is conducted using a measurement system utilizing a tracking-type laser interferometer, laser light is emitted at a retroreflector, the tracking-type laser interferometer is placed in a tracking state, and a displacement body is displaced to a desired point and a combination of position data of the displacement body at a single desired location and rotation position data of a biaxial rotation mechanism from the tracking-type laser interferometer is stored. When a received light determiner determines that there is an abnormality in an amount of light, the positions of the displacement body and the biaxial rotation mechanism are maintained, and the displacement body and biaxial rotation mechanism are displaced to the respective stored, predetermined positions. When the abnormality in the amount of received light is eliminated after displacement, the tracking-type laser interferometer is placed in the tracking state and measurement is restarted.

Abstract: Laser radar systems include a pentaprism configured to scan a measurement beam with respect to a target surface. A focusing optical assembly includes a corner cube that is used to adjust measurement beam focus. Target distance is estimated based on heterodyne frequencies between a return beam and a local oscillator beam. The local oscillator beam is configured to propagate to and from the focusing optical assembly before mixing with the return beam. In some examples, heterodyne frequencies are calibrated with respect to target distance using a Fabry-Perot interferometer having mirrors fixed to a lithium aluminosilicate glass-ceramic tube.

Abstract: A force detector and method for using the same includes a lens. A cantilever is below the movable lens. A laser above the movable lens emits a beam of light through the movable lens, such that light reflects from the lens and the cantilever. A camera is configured to capture images produced by the light reflected from the lens and the light reflected from the cantilever. A processor is configured to determine a force between the movable lens and the cantilever based on a change in phase of the interference rings.

Abstract: A 3D coordinate measuring system includes a six-DOF unit having a unit frame of reference and including a structure, a retroreflector, a triangulation scanner, and an augmented reality (AR) color camera. The retroreflector, scanner and AR camera are attached to the structure. The scanner includes a first camera configured to form a first image of the pattern of light projected onto the object by a projector. The first camera and projector configured to cooperate to determine first 3D coordinates of a point on the object in the unit frame of reference, the determination based at least in part on the projected pattern of light and the first image. The system also includes a coordinate measuring device having a device frame of reference and configured to measure a pose of the retroreflector in the device frame of reference, the measured pose including measurements of six degrees-of-freedom of the retroreflector.

Abstract: In one general aspect, a system for determining a motion of an object includes a laser system configured to generate range and velocity measurements of a plurality of points on the object and a processor. The processor is configured to determine, from the range and velocity measurements of the plurality of points on the object, a rotation of the object. In some aspects, the processor is also configured to determine, from the range and velocity measurements of the plurality of points on the object and the rotation of the object, a distance moved by the object between a first time and a second time.

Abstract: The invention relates to a laser tracker for determining a position and/or orientation of an auxiliary measurement object, comprising a base which defines a vertical axis, a pivotal support, and a rotatable pivoting unit with at least two optical assemblies and an image detecting unit. The optical assemblies can be moved along an optical axis of the pivoting unit, and a magnification factor is defined by a positioning of the optical assembly. The tracker further has a radiation source for emitting a laser beam, a distance measuring unit, an angle measuring functionality, and a control and processing unit with an object imaging functionality, wherein the optical assemblies are positioned relative to the auxiliary measurement object dependent on a triggered measurement such that an image is provided for the auxiliary measurement object on the image detecting unit with a particular image scale.

Abstract: An optical component includes a component body, and at least one angled-facet waveguide formed in the component body, wherein the angled-facet waveguide is substantially mirror-symmetrical in shape relative to a line at or near the center of the angled-facet waveguide.

Abstract: The polishing amount of an optical fiber component can be measured directly, accurately and easily in a real-time mode during polishing, regardless of the polishing amount of a ferrule. Provided is a method for measuring the polishing amount of an optical fiber component while performing polishing, the method including: branching an inspection light among a reference optical path having a variable optical path length, an optical fiber component being measured, and a comparison optical path, and determining a polishing amount of the optical fiber component by a change amount of a difference Lc between a reference optical path length when return light of the reference optical path interferes with return light of the optical fiber component being measured and a reference optical path length when the return light of the reference optical path interferes with return light of the comparison optical path.

Abstract: A method for measuring a distance includes modulating the light beam at a first frequency, receiving a second beam by the optical detector to produce a first electrical signal having the first frequency and a first phase; modulating the light beam at a second frequency different than the first frequency; receiving the second beam by the optical detector to produce a second electrical signal having the second frequency and a second. After these steps, the retroreflector is moved while modulating the light beam continuously at the second frequency; and a first distance to the retroreflector is determined based at least in part on a the first and second frequencies and phases.

Abstract: A coordinate measuring device includes a carrier that automatically rotates about two axes and can be directed toward a measuring aid. The following are arranged on the carrier so as to be able to move together: a device for optically measuring the distance to the measuring aid; a first light source for emitting a target beam that is visible as a first target point when reflected on the measuring aid; a detection unit for determining a fine position of the first target point on a first position detection sensor; a second light source, the light of which is visible as a second target point when reflected on the measuring aid; a rough target detection unit for determining a rough position of the second target point on a second position detection sensor. A control device directs the carrier toward the measuring aid according to the fine and rough positions.

Abstract: An optical device includes an optical grating coupler and a plurality of optical waveguides coupled thereto. The optical grating coupler is formed along a planar surface of a substrate, and includes a pattern formed by ridges concentrically located on the surface about a center thereon. Each adjacent pair of ridges is separated by a groove. Each waveguide of the plurality of waveguides is oriented about radially with respect to the center, and has a first end that terminates near an outermost one of the ridges. The first ends are about uniformly spaced along the outermost one of the ridges.

Abstract: An extrinsic optical fiber device for measuring a physical parameter, includes: a light source, of central wavelength ?, an optical fiber projecting, a unit for detecting an interferometric signal, the interferometric signal including the information about the physical parameter to be determined, elements for modulating a signal emitted by the light source, elements for calculating the physical parameter on the basis of the interferometric signal measured by the detection unit. The modulated signal from the light source includes an alternating component including a double frequency modulation generated by the modulation elements. The main application of this device is the measurement of the displacement of a target.

Abstract: A method and installation for inspecting a butt weld of transverse ends of metal strips held together between first and second jaws along the ends, include leaving an interstice between the jaws for passage of a first transmission channel of incident waves generating ultrasound waves on one surface of the first strip and enabling passage of a second transmission channel of waves emerging from the surface of the second strip. The incident waves of the first channel are generated using laser pulses in an operating state implementing a third channel of waves generated on the surface of the first strip, passing through the weld, and emerging in the second channel. Weld inspection characteristics are identified by analyzing the operating state related to the pulses and a measurement of a signature of a vibration state of the surface of the second strip upon emergence of the waves in the second channel.

Abstract: A method and system described for sensing a displacement by receiving and propagating a laser light signal with an etched waveguide that is configured to enable an evanescent optical field above the waveguide surface. A movable perturber can be positioned so the perturber interacts with the evanescent optical field above the waveguide surface. An optical phase shift can be induced in the waveguide when the movable perturber is displaced in the evanescent optical field, and the optical phase shift can be measured with an optical readout circuit.

Abstract: A compact, balanced, up to three degrees of freedom measuring interferometer which enables fiber delivery of an optical source without periodic nonlinearity, an interferometer system, and method for using an interferometer to measure up to three degrees of freedom is disclosed.

Abstract: A position-measuring device for detecting the position of two objects movable relative to each other, includes a measuring standard that is joined to one of the two objects, as well as a scanning system for scanning the measuring standard, the scanning system being joined to the other of the two objects. The scanning system permits a simultaneous determination of position along a first lateral shift direction and along a vertical shift direction of the objects. To that end, on the part of the scanning system, two scanning beam paths are formed, in which a group of phase-shifted signals is able to be generated in each case at the output end from interfering partial beams of rays. In addition, via the scanning system, at least a third scanning beam path is formed, by which it is possible to determine position along a second lateral shift direction of the objects.

Abstract: A position detection system is able to detect the three dimensional position of at least one target (10). Each target (10) is configured to act as a retro-reflector for light incident from any direction. At least one light emitter illuminates the at least one target (10) and at least one detector (24) is provided for detecting and taking measurements of light retro-reflected from a target (10). There is also provided a processor for processing measurements taken by each detector (24) to determine the three dimensional position of the at least one target (10).

Abstract: A distance measuring device includes a light source emitting light, and an integrated electro-optic modulator arranged such that the emitted light passes through an optical waveguide of the electro-optic modulator in a first direction before being emitted from the distance measuring device, and after being reflected from a target passes through the electro-optic modulator in a second direction which is opposite to the first direction. The forward electro-optic response of a modulating region of the electro-optic modulator is the same as the backward electro-optic response, and a center of gravity of the modulation is independent of modulation frequency.

Abstract: An optical probe system has a light source fiber-delivered and the detector fiber-coupled for analyzing carrier fringes using a line sensor to measure displacement and tilt. Simultaneous surface metrology to measure both the front and back surface of the same optic, is enabled provided the two surfaces are substantially parallel to within the measurement range. Alternatively, the front surface can be measured and then subsequently the back surface.

Abstract: An electro-optic modulator includes a waveguide of a nonlinear optical material and an electrode line for generating an electrical field in a modulating region of the waveguide when a voltage is applied to the electrode line, thereby modulating light passing through the waveguide. Therein, the forward electro-optic response of the modulating region is the same as the backward electro-optic response; and the electro-optic response has a band-pass or a low-pass characteristic. A distance measuring device includes a light source emitting light, and such an electro-optic modulator arranged such that the emitted light passes through the electro-optic modulator in a first direction before being emitted from the distance measuring device, and after being reflected from a target passes through the electro-optic modulator in a second direction which is opposite to the first direction.

Abstract: A material sensing apparatus comprises an excitation source configured to induce waves in a workpiece, and an optical waveguide interferometer configured to sense the induced waves in the workpiece. The optical waveguide interferometer comprises a probe segment having a probe segment end, and an adjustable coupler configured to permit setting a gap between the probe segment end and the workpiece. A controller is coupled to the adjustable coupler and configured to set the gap between the probe segment end and the workpiece.

Abstract: A measurement device (120) includes a light director and a spatial light modulator (130). The light director is disposed to direct light to the spatial light modulator (130) and the spatial light modulator (130) is disposed to receive light from the light director and to modulate it to form an intensity pattern. An optical element is disposed to receive light which formed the intensity pattern and is arranged to magnify the intensity pattern into a measurement space. A detector (142) is disposed to detect light reflected from the measurement space.

Abstract: Swing-style demodulation device for measuring displacement information, including (1) a broadband light source, (2) an optical circulator, (3) GRIN lens, (4) a fixed mirror on an object under test, (5) a collimating device, (6) a rotating mirror, (7) f-? lens, (8) a polarizer, (9) a narrow strip shaped birefringent wedge, (10) a polarization analyzer, and (11) a signal acquisition system.

Abstract: In part, aspects of the invention relate to methods, apparatus, and systems for intensity and/or pattern line noise reduction in a data collection system such as an optical coherence tomography system that uses an electromagnetic radiation source and interferometric principles. In one embodiment, the noise is intensity noise or line pattern noise and the source is a laser such as a swept laser. One or more attenuators responsive to one or more control signals can be used in conjunction with an analog or digital feedback network in one embodiment.

Abstract: A measuring device for the high-precision optical determination of distance or position includes a light source, at least one optical functional element in the form of a plane mirror or a measuring standard, and a detector system. At least two sub-beams are generated, of which at least one impinges on the functional element at least three times before the sub-beams propagate, interferingly superposed, in the direction of the detector system, via which at least one phase-encoded measuring signal is able to be generated from the superposed sub-beams. Between the impingements on the optical functional element, the sub-beam passes through at least two imaging elements, the imaging elements having imaging factors such that no location and directional shear of the interfering sub-beams results in the event the optical functional element tilts out of its setpoint position.

Abstract: A vortex flowmeter having a optical fiber channel in the device wall, a first sealing element extending into the fiber channel with a contact surface for the optical fiber and at least a second sealing element with a contact surface for the optical fiber, wherein second sealing element being guided in a guide in the device wall. In a sealed state of the fiber fiber channel, the second sealing element is pressed against the contact surface of the first sealing element by a positioning means with the optical fiber located between the contact surfaces of the sealing elements and enclosed thereby, and in this manner, the fiber channel is closed by the first sealing element, the second sealing element and the optical fiber guided between the first sealing element and the second sealing element.

Abstract: A vortex flowmeter having a measuring tube through which a medium can flow, a bluff body in the measuring tube and a pressure sensor in the effective range of the bluff body. The pressure sensor has a deflectable measuring diaphragm for determining the pressure in the medium neighboring the measuring diaphragm, at least one optical fiber being arranged on and/or in the measuring diaphragm for detecting the deflection of the measuring diaphragm. The optical fiber is at least partially effectively connected to the measuring diaphragm along its length so that a deflection of the measuring diaphragm caused by the medium pressure leads to an extension and/or compression of the optical fiber. The pressure sensor has a pocket that can be deflected by the pressure of the medium and which surrounds the measuring diaphragm and optical fiber to protect them from the medium. The measuring diaphragm is deflected with the pocket.

Abstract: A sensor compares frames of pixels representing a speckle pattern caused by interference of light through an optical fiber to detect magnitudes of deflection of the fiber. A coherent light source illuminates the optical fiber. An image sensor captures the speckle pattern and frames of pixels produced by the image sensor are processed to determine deflection. A baseline frame is generated from frames previously received. Each frame is compared to the baseline frame to determine the cumulative amount of deflection on the fiber. To compensate for drift and large-scale movements of the optical fiber, the baseline frame is updated as frames are received. The processed output from comparing to the baseline frame has larger amplitude signals than from comparing to adjacent frames due to larger deflections over time since the baseline frame. Signal-to-Noise ratio is improved, and the processed output better matches a plot of the actual total deflection.