Abstract: A device includes a first resonating cavity and a second resonating cavity. The first resonating cavity includes a first end surface and a second end surface. The first resonating cavity has a first free spectral range. The first free spectral range is a first frequency of a wavelength dependent ripple in a gain of the device that is a function of a first distance between the first end surface and the second end surface. The second resonating cavity includes a third end surface and a fourth end surface. A second distance between the third end surface and the fourth end surface is set such that an amplitude of the wavelength dependent ripple is reduced.

Abstract: An optical detector system comprises a hermetic optoelectronic package, an optical bench installed within the optoelectronic package, a balanced detector system installed on the optical bench. The balanced detector system includes at least two optical detectors that receive interference signals. An electronic amplifier system installed within the optoelectronic package amplifies an output of at least two optical detectors. Also disclosed is an integrated optical coherence tomography system. Embodiments are provided in which the amplifiers, typically transimpedance amplifiers, are closely integrated with the optical detectors that detect the interference signals from the interferometer. Further embodiments are provided in which the interferometer but also preferably its detectors are integrated together on a common optical bench. Systems that have little or no optical fiber can thus be implemented.

Abstract: An optical coherence tomography system comprising a light source (a) and a probe (e) that has a window at a front facing end. The window has an inner face (i) that has an anti-reflection surface and allows light from the source to pass through it, and an outer face (j) that reflects some of the light from the source and transmits some of the light to and from the sample (k). The reflected light acts as a reference.

Abstract: According to one aspect, the invention relates to a device (20) for three-dimensional imaging by full-field interferential microscopy of a volumic and scattering sample (1) comprising an emission source (201) for emitting an incident wave with low temporal coherence, an imaging interferometer (200) of variable magnification, allowing for the acquisition of at least one first and one second interferometric images resulting from the interference of a reference wave obtained by reflection of the incident wave on a reference mirror (205) and an object wave obtained by backscattering of the incident wave by a slice of the sample at a given depth of the sample, the at least two interferometric images having a phase difference obtained by varying the relative path difference between the object and reference arms of the interferometer, a processing unit (206) for processing said interferometric images making it possible to obtain a tomographic image of said slice of the sample, means for axially displacing the interf

Abstract: Methods, systems, and devices are disclosed for implementing Doppler optical coherence tomography and microangiography imaging. In one aspect, a device for optically measuring a sample includes a swept light source to produce an input beam of coherent light for optically probing a target area of a sample, a waveguide to guide the input beam in two independent propagation modes, an optical probe to reflect a first propagation mode back to the waveguide and to direct a second propagation mode to the sample and to overlap the reflection from the sample with the first propagation mode, a differential delay controller to produce variable relative phase delays between the first propagation mode and the second propagation mode, a detection module to combine the first propagation mode and the second propagation mode and to extract information of the sample, and a processing unit to process the information to produce optical images.

Abstract: Systems and methods for increasing the duty cycle and/or producing interleaved pulses of alternating polarization states in swept-source optical coherence tomography (OCT) systems are considered. Embodiments including improved buffering, frequency selecting filter sharing among multiple SOAs, intracavity switching, and multiple wavelength bands are described. The unique polarization properties of the source configurations have advantages in speckle reduction, polarization-sensitive measurements, polarization state dependent phase shifts, spatial shifts, and temporal shifts in OCT measurements.

Abstract: The present invention relates to an apparatus for low coherence optical imaging, and more particularly to an apparatus for low coherence optical imaging which can obtain the information of the different depths of a sample simultaneously. The apparatus comprises a phase transformation unit or a beam shift unit. The phase transformation unit or beam shift unit transforms and reflects the reference light, such that the reflected reference light comprises different phases at the different positions of a cross-section. When the reference light and a information light from the sample are superimposed on a photo detector, the information of the different depths of the sample is obtained. By using the apparatus of the present invention, the elements, the volume, and the cost of the apparatus are reduced. Because of only two-dimensional scanning is required, the scanning rate is improved.

Abstract: Exemplary method, apparatus and arrangement can be provided for obtaining information associated with a sample such as a portion of an anatomical structure. The information can be generated using first data, which can be based on a signal obtained from a location on the sample, and second data, where the second data can be obtained by combining a second signal received from the sample with a third reference signal. An image of a portion of the sample can also be generated based on the information. For example, the first data can be associated with spectral encoding microscopy data, and the second data can be associated with optical coherence tomography data.

Abstract: Systems for extended depth frequency domain optical coherence tomography are provided including a detection system configured to sample spectral elements at substantially equal frequency intervals, wherein a spectral width associated with the sampled spectral elements is not greater than one-half of the frequency interval. Related methods are also provided herein.

Abstract: The time delay (and therefore the OPD) between object and reference beams in an interferometer is manipulated by changing the spectral properties of the source. The spectral distribution is tuned to produce a modulation peak at a value of OPD equal to the optical distance between the object and reference arms of a Fizeau interferometer, thereby enabling the use of its common-axis configuration to carry out white-light measurements free of coherence noise. Unwanted interferences from other reflections in the optical path are also removed by illuminating the object with appropriate spectral characteristics. OPD scanning is implemented without mechanical means by altering the source spectrum over time so as to shift the peak location by a predetermined scanning step between acquisition frames. Finally, the spectrum is controlled on a pixel-by-pixel basis to create a virtual surface that matches the profile of a particular sample surface.

Abstract: An optical coherence tomography (OCT) apparatus includes an optical source, an interferometer generating an object beam and a reference beam, a transverse scanner for scanning an object with said object beam, and a processor for generating an OCT image from an OCT signal returned by said interferometer. At least the optical source, the interferometer, and the scanner are mounted on a common translation stage displaceable towards and away from said object. A dynamic focus solution is provided when the scanner and a folded object path are placed on the translation stage.

Abstract: A mirror image suppression method adapted to an optical coherence tomography (OCT) system is provided. The mirror image suppression method includes the following steps: obtaining a tomography image of an object to be tested by using the OCT system; calculating one real image signal obtained from an nth specific-mode scan for a specific pixel of the tomography image based on image signals obtained from an (n?1)th and the nth specific-mode scans; obtaining one real image signal of each of a plurality of pixels in the tomography image based on the calculation in the step of calculating the one real image signal; and reconstructing the tomography image based on the real image signal of each of the pixels obtained in the step of obtaining the one real image signal to suppress mirror image signals of the tomography image.

Abstract: A system, method, and device for imaging a sample. In embodiments, a light from a low-coherence source or a wavelength-swept source is used to illuminate the sample. Pathlength-resolved intensity profiles of the light reemitted from the sample are recorded and measurements are taken. A reconstruction algorithm is used to invert the pathlength-resolved measurements to form an image.

Abstract: The present invention discloses a method for generating elevation maps or images of a tissue layer/boundary with respect to a fitted reference surface, comprising the steps of finding and segmenting a desired tissue layer/boundary; fitting a smooth reference surface to the segmented tissue layer/boundary; calculating elevations of the same or other tissue layer/boundary relative to the fitted reference surface; and generating maps of elevation relative to the fitted surface. The elevation can be displayed in various ways including three-dimensional surface renderings, topographical contour maps, contour maps, en-face color maps, and en-face grayscale maps. The elevation can also be combined and simultaneously displayed with another tissue layer/boundary dependent set of image data to provide additional information for diagnostics.

Abstract: In one aspect, the invention relates to a method of acquiring optical coherence tomographic data from a sample. The method includes the steps of scanning a first location on the sample to obtain a first set of optical coherence tomographic data, scanning a second location on the sample to obtain a second set of optical coherence tomographic data, and defining a fiducial position relative to a location on the sample using one of the two sets of optical coherence tomographic data. In one embodiment, the first set of optical coherence tomographic data is survey data. However, in another embodiment the first set of optical coherence tomographic data is sample measurement data.

Abstract: Subject matter disclosed herein relates to measuring optical fibers or measuring devices comprising optical fibers and, in particular, to measuring a variation of refractive index of an optical fiber as a function of position and wavelength.

Abstract: A prism is attached to a refractive index dispersion lens by inclining the incident plane of the prism by a prescribed angle with respect to the end face of the refractive index dispersion lens and filling adhesive therebetween. In this way, the amount of light reflected from the bottom plane of the prism decreases in accordance with the angle of inclination of the incident plane, and the interference signal formed by the reflected light from the bottom plane of the prism, and the reflected light of a reference beam therefore weakens and the image signal decreases. Consequently, distinguishing between the image signal and the image signals produced by reflected light from the measurement subject is facilitated.

Abstract: A low coherence enhanced backscattering tomography (LEBT) method is disclosed for depth-selective sensing of the superficial layer of tissue. 3D images of the microarchitecture and molecular conformation of the superficial layer of tissue are obtained. The method combines the high resolution advantage of low coherence light and the high sensitivity advantage of light scattering to tissue structure and composition. Intact tissue can be examined without the need of excision or processing. The method can be applied in in situ measurements. According to the method, 3D images of the nuclear morphology and cellular structure for the superficial layer of the tissue are generated; this is particularly useful in detecting cancer and precancer at the earliest stage of carcinogenesis.

Abstract: The disclosed automatic calibration systems and methods provide a repeatable way to detect internal catheter reflections and to shift the internal catheter reflections to calibrate an image.

Abstract: Disclosed is a method and apparatus for the non-invasive selection of high-quality seeds, based on optical coherence tomography, by which pathogen-infected and pathogen-free seeds can be discriminated in a non-invasive manner. The apparatus is operated by the processes of scanning a seed of diagnostic interest in a non-invasive manner using an optical coherence tomographic unit; processing interference signals of the scanned tomographic images to produce tomographic image data of the seed of diagnostic interest; analyzing the tomographic image data; comparing the analyzed tomographic image data with preset reference tomographic image data; diagnosing the seed of diagnostic interest as a pathogen-infected or pathogen-free seed according to the comparison data; and selecting high-quality seeds according to the diagnosis data. It can screen high-quality seeds with rapidity, convenience, and accuracy at a low cost and is industrially applicable, making a great contribution to agricultural quarantine inspection.

Abstract: An optical coherence tomography method according to the present invention comprising the steps of dividing an object to be measured into a plurality of measurement regions adjacent to one another in a direction of irradiation of a measurement light, and acquiring a measurement image for every measurement region based on a wavelength spectrum of a coherent light and acquiring a tomographic image for every measurement region by removing a mirror image of a tomographic image of an adjacent region being adjacent to the measurement region of the measurement image from the measurement image.

Abstract: The present invention relates to a non-invasive early diagnostic method and device that allows an early diagnosis of Marssonina blotch disease, which infects apple tree leaves, before the occurrence of lesions to enable early prevention of apple Marssonina blotch disease.

Abstract: An apparatus and method are provided. In particular, at least one first electro-magnetic radiation may be provided to a sample and at least one second electro-magnetic radiation can be provided to a non-reflective reference. A frequency of the first and/or second radiations varies over time. An interference is detected between at least one third radiation associated with the first radiation and at least one fourth radiation associated with the second radiation. Alternatively, the first electro-magnetic radiation and/or second electro-magnetic radiation have a spectrum which changes over time. The spectrum may contain multiple frequencies at a particular time. In addition, it is possible to detect the interference signal between the third radiation and the fourth radiation in a first polarization state. Further, it may be preferable to detect a further interference signal between the third and fourth radiations in a second polarization state which is different from the first polarization state.

Abstract: An image forming method uses an optical coherence tomography as to an optical axis direction of plural pieces of image information of an object. First image information of an object is obtained at a first focus with respect to an optical axis direction to then object. A focusing position is changed by dynamic focusing from the first focus to a second focus along the optical axis. The second image information of the object is obtained at the second focus. A third image information, tomography image information of the object and including a tomography image of the first focus or the second focus, is obtained by Fourier domain optical coherence tomography. A tomography image or a three-dimensional image of the object is formed in positional relation, in the optical axis direction, between the first image information and the second image information using the third image information.

Abstract: A system and method for sweeping electromagnetic radiation over a first coherence length and a second length over a range of wavelengths to generate an image. Electromagnetic radiation having a first coherence length is generated and swept over a range of wavelengths. Electromagnetic radiation having a second coherence length is generated and swept over a range of wavelengths. The electromagnetic radiation is splitting through a reference path and a sample path; Electromagnetic radiation returned from the reference path and the sample path is detected, wherein the detector generates output signals corresponding to the received electromagnetic radiation. In one embodiment, the output signals are processed to generate an image. The image may be interleaved with data corresponding to the electromagnetic radiation having the first coherence length and the second coherence length.

Abstract: An optical coherence tomography system having real-time artifact and saturation correction includes an optical coherence tomography unit, and a signal processing and display system adapted to communicate with the optical coherence tomography unit to receive imaging signals therefrom. The optical coherence tomography system is a Fourier Domain optical coherence tomography system. The signal processing and display system includes a parallel processor configured to correct the imaging signals, in real time, to at least partially remove image artifacts and saturation based on a subset of image data within an image frame.

Abstract: Apparatus include a microscope including an objective and a stage for positioning a test object relative to the objective, the stage being moveable with respect to the objective, and a sensor system, that includes a sensor light source, an interferometric sensor configured to receive light from the sensor light source, to introduce an optical path difference (OPD) between a first portion and a second portion of the light, the OPD being related to a distance between the objective lens and the stage, and to combine the first and second portions of the light to provide output light, a detector configured to detect the output light from the interferometric sensor, a fiber waveguide configured to direct light between the sensor light source, the interferometric sensor and the detector, a tunable optical cavity in a path of the light from the sensor light source and the interferometric sensor, and an electronic controller in communication with the detector, the electronic controller being configured to determine in

Abstract: Portable optical coherence tomography (OCT) devices including at least one mirror configured to scan at least two directions are provided. The portable OCT devices are configured to provide a portable interface to a sample that can be aligned to the sample without repositioning the sample. Related systems are also provided.

Abstract: An optical imaging method is provided that can realize, at low cost, the extension of the imaging depth range. An optical imaging apparatus 400 is an apparatus that forms a tomographic image of an object using FD-OCT, and performs a scanning step, detection step and imaging step. In the scanning step, the object is scanned with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences. In the detection step, interference light of the signal light passing through the object and the reference light is detected. In the imaging step, a tomographic image of the object is formed based on the detection results of a plurality of the interference lights sequentially obtained in the detection step according to the scanning.

Abstract: Provided is a device for determining the surface topology and associated color of a structure, such as a teeth segment, including a scanner for providing depth data for points along a two-dimensional array substantially orthogonal to the depth direction, and an image acquisition means for providing color data for each of the points of the array, while the spatial disposition of the device with respect to the structure is maintained substantially unchanged. A processor combines the color data and depth data for each point in the array, thereby providing a three-dimensional color virtual model of the surface of the structure. A corresponding method for determining the surface topology and associated color of a structure is also provided.

Abstract: A free-space Michelson Interferometer-based Dual Detection Frequency Domain-Optical Coherency Tomography (DD-FD-OCT) apparatus includes a non-polarizing beam splitter that can be used to misalign sample and reference beam paths to provide a stable ?/2 phase shift between simultaneously detected interfering sample and reference beams to eliminate the mirror image created by Fourier transformation during image reconstruction. A hybrid fiber system Mach Zehnder Interferometer- and free-space Michelson Interferometer-based Dual Detection Frequency Domain-Doppler Optical Coherency Tomography (DD-FD-DOCT) apparatus provides higher power efficiency and thus better sensitivity compared to the free-space DD-FD-OCT. Both DD-FD-OCT systems enable functional imaging with the contrasts of Doppler and that of polarization, in addition to full range images simultaneously.

Abstract: A system and method for measuring an interferometric signal from a swept-wavelength interferometer by scanning a tunable laser source over two wavelength ranges, whose centers are separated substantially more than the length of wavelength ranges. The spatial resolution of the measurement is determined by the inverse of the wavelength separation between a first and second wavelength region, as well as by the wavelength range of the first and second regions. An electronically tunable laser may be utilized to produce two wavelength ranges that are widely separated in wavelength. Such a system and method has wide applications to the fields of optical frequency domain reflectometry (OFDR) and swept-wavelength optical coherence tomography (OCT), for example.

Abstract: An apparatus and method are provided. In particular, at least one first electro-magnetic radiation may be provided to a sample and at least one second electro-magnetic radiation can be provided to a non-reflective reference. A frequency of the first and/or second radiations varies over time. An interference is detected between at least one third radiation associated with the first radiation and at least one fourth radiation associated with the second radiation. Alternatively, the first electro-magnetic radiation and/or second electro-magnetic radiation have a spectrum which changes over time. The spectrum may contain multiple frequencies at a particular time. In addition, it is possible to detect the interference signal between the third radiation and the fourth radiation in a first polarization state. Further, it may be preferable to detect a further interference signal between the third and fourth radiations in a second polarization state which is different from the first polarization state.

Abstract: Systems and methods for reducing noise in balanced detection based optical coherence tomography (OCT) systems are described. Embodiments including both optical hardware and electronic based solutions to spectrally filter and attenuate the source reference light in optical coherence tomography in an effort to reduce RIN and FPN noise in OCT systems are presented. A novel application to electronic balanced detection schemes in which a single source of reference detection is balanced against the interferometric signals from multiple interferometers is also presented.

Abstract: An imaging apparatus capturing optical coherence tomographic images of a test object based on a plurality of combined light beams that are obtained by combining a plurality of return light beams from the test object irradiated with a plurality of measurement light beams and a plurality of reference light beams respectively corresponding to the plurality of measurement light beams, the apparatus including: an instruction unit configured to give instructions about amounts of changes in respective optical path length differences between the plurality of reference beams and the plurality of return light beams; and a change unit configured to change the optical path length differences based on the amounts of changes instructed by the instruction unit.

Abstract: A system and method for excitation generation in soft-field tomography are provided. One method includes applying a plurality of phase modulated (or phase and amplitude modulated) excitations to a plurality of transducers of a data acquisition system positioned proximate a surface of an object and measuring a response to the applied phase modulated (or phase and amplitude modulated) excitations at the plurality of transducers. The method also includes determining a property of the object based on the measured responses.

Abstract: The invention relates to an optical coherence microscopy system for fast, phase resolved imaging by means of optical coherence microscopy with decoupled illumination and detection apertures, producing a dark-field effect with an enhanced optical contrast. The setup uses a light source with an appropriate temporal coherence, an interferometer and an array detector combined with a spectrometer. The dark-field effect is produced by optical filter means in the illumination and detection paths, positioned in conjugated planes of the sample microscope objective. These optical means comprise for example refractive or diffractive elements, amplitude or phase masks, or programmable spatial light modulators. The object is scanned via a scanning unit allowing a point scan of the object.

Abstract: In part, the invention relates to a lens assembly. The lens assembly includes a micro-lens; a beam director in optical communication with the micro-lens; and a substantially transparent film. The substantially transparent film is capable of bi-directionally transmitting light, and generating a controlled amount of backscatter. In addition, the film surrounds a portion of the beam director.

Abstract: An imaging apparatus according to the present invention can cause a display unit to display a scanning range of each of a plurality of measurement light beams in an intersection image (an image in a direction intersecting a direction in which an inspection object is irradiated with the plurality of measurement light beams) of the inspection object.

Abstract: A tomographic imaging apparatus configured to acquire a tomographic image or a cross-sectional image of an object to be examined from signals of a plurality of interfering beams obtained by emitting a plurality of measuring beams to the object to be examined and causing return beams of the measuring beams to interfere with reference beams includes a sensor configured to detect the plurality of interfering beams to acquire signals of the plurality of interfering beams, an acquisition unit configured to acquire an optical characteristic in the tomographic imaging apparatus corresponding to each of the plurality of interfering beams, and a generation unit configured to generate a tomographic image or a cross-sectional image of the object to be examined based on the signals of the plurality of interfering beams and the optical characteristic.

Abstract: A tomographic imaging apparatus includes an irradiation unit configured to irradiate with a plurality of measurement light beams, a sensor configured to convert into an electric signal a plurality of combined light beams via an optical imaging system by making return light beams from an inspection target, which are generated due to the plurality of measurement light beams, interfere with reference light beams, an output unit configured to output light beams of a single wavelength based on a wavelength width of the plurality of measurement light beams, and a generation unit configured to generate a tomographic image from an electric signal acquired by the sensor via the imaging optical system, based on a position of the light beam of the single wavelength on the sensor.

Abstract: In order to reduce a width in a scanning direction with respect to an arrangement of measurement lights and to obtain a tomogram with a high SN ratio, an imaging apparatus according to the present invention adjusts an arrangement of a plurality of measurement lights in an object to be examined with respect to a scanning direction of a scanning unit for scanning the object to be examined with the plurality of measurement lights, based on a detection result of a detection unit for detecting the arrangement of the plurality of measurement lights.

Abstract: In order to perform accurate evaluation for enhanced depth imaging (EDI) in which a tomographic image of a retina has a low luminance value in large part, provided is an optical coherence tomographic imaging apparatus for acquiring an image of an object to be inspected by irradiating the object to be inspected with measuring light and causing return light from the object to be inspected to interfere with reference light, the optical coherence tomographic imaging apparatus including: a unit for setting an imaging parameter of the image; a unit for selecting an image quality evaluation index in accordance with the imaging parameter; a unit for acquiring an image characteristic amount from the acquired image in accordance with the set imaging parameter; and a unit for evaluating image quality of the image based on the image characteristic amount and the image quality evaluation index.

Abstract: A digitized image of an object may include representations of portions of the object that are obscured, occluded or otherwise unobservable. The image may be a multi-dimensional visual representation of dentition. Characteristics of the dentition and its surfaces, contours, and shape may be determined and/or analyzed. A light may be directed toward and reflected from the dentition. The reflected light may be combined with a reference to determine characteristics of the dentition, including obscured areas such as subgingival tissue.

Abstract: A method and apparatus are provided for a swept source optical coherence tomography (OCT) system utilizing a fast scanning mechanism in the sample arm and a slowly swept light source. The position data is collected rapidly while the wavelength of the source is swept slowly. The system reduces the sweep speed requirements of the light source enabling higher power, greater imaging range, and linear sweeps of the source frequency. The OCT components (or most of them) may be implemented within a hand held imaging probe. In operation, a triangulation scan may be used to orient the imaging probe with respect to a fixed coordinate system; preferably, OCT data captured by the device is then transformed to that same orientation with respect to the fixed coordinate system to improve the scanning results.

Abstract: Provided is a semiconductor optical integrated device, formed by arranging a light emitting element and a light detecting element in a plane of the same substrate, each formed by laminating layers which at least include a first clad layer of a first conductive type, an active layer and a second clad layer of a second conductive type on a substrate, wherein the active layer has a structure where a second active area of a conductive type and an undoped first active area are laminated, and the second active area has the same conductive type as that of the first or second clad layer laminated in the closest position to the second active area. This device suppresses heat generation due to increased operating current and unnecessary light generation at an operation of the light emitting element, and enhancing light absorption efficiency at the an operation of the light emitting element.

Abstract: In one embodiment, imaging a medium under evaluation includes generating acquired images of the medium, each acquired image comprising a cross-sectional image along a lateral and a depth direction of the medium that results from scanning the medium at a different depths, filtering each acquired image to remove out-of-focus portions of the images and generate filtered images, and merging the filtered images to form a high-resolution fused image.

Abstract: The invention relates to a system and to a corresponding method for optical coherence tomography having a light source (15) for producing light (14), a first interferometer (10), a second interferometer (20) and an optical fiber (17) by means of which light emitted by the first interferometer (10) is conveyed to the second interferometer (20). For simpler and more efficient injection of the light emitted by the first interferometer (10) into the optical fiber (17) provision is made such that light is injected into the first interferometer (10) which has a first number of transversal modes, and the optical fiber (17) has at least one multi-mode fiber into which the light passing out of the first interferometer (10) is injected such that in the optical fiber (17) a second number of transversal modes is stimulated which is conveyed to the second interferometer (20), the second number of transversal modes being substantially greater than the first number of transversal modes.

Abstract: The invention relates to a test device for testing a bonding layer between wafer-shaped samples and a test process for testing the bonding layer. The test device comprises a measuring head for an OCT process that is configured to direct an optical measuring beam at a composite comprising at least two wafer-shaped samples with a bonding layer positioned between them. An optical beam splitter is configured to divert an optical reference beam as a reference arm for distance measurements. An evaluation unit is configured to evaluate layer thickness measurements without a reference arm and distance measurements with a reference arm. An optical switch device is configured to connect and disconnect the reference arm.

Abstract: A system and method for imaging of a sample, e.g., biological sample, are provided. In particular, at least one source electro-magnetic radiation forwarded to the sample and a reference may be generated. A plurality of detectors may be used, at least one of the detectors capable of detecting a signal associated with a combination of at least one first electro-magnetic radiation received from the sample and at least one second electro-magnetic radiation received from the reference. At least one particular detector may have a particular electrical integration time, and can receive at least a portion of the signal for a time duration which has a first portion with a first power level greater than a predetermined threshold and a second portion immediately preceding or following the first portion. The second portion may have a second power level that is less than the predetermined threshold, and extends for a time period which may be, e.g., approximately more than 10% of the particular electrical integration time.