Time-multiplexed spectrally controlled interferometry

    公开(公告)号:US09696211B2

    公开(公告)日:2017-07-04

    申请号:US14927320

    申请日:2015-10-29

    Applicant: Artur Olszak

    Inventor: Artur Olszak

    Abstract: A tunable light source having a temporal coherence length such that interference fringes are detected within the optical path difference of the interferometer is spectrally controlled to produce multiple wavelengths during sequential fractions of the integration time of the detector of the interferometer. The wavelengths are selected so as to produce a visible correlogram at each integration time according to spectrally controlled interferometry (SCI) principles. Such different wavelengths may be produced by stepwise or continuous modulation. The modulation step is repeated sequentially while changing the period of modulation to produce a succession of predetermined spatial patterns of interference fringes, as required for interferometric measurements. The approach enables the practice of SCI with common-path apparatus used for conventional phase shifting, thereby combining the advantages of high-coherence and white-light interferometry. A suitable time-modulated source combines a coherent source with an optical modulator and a waveform generator synchronized with the source.

    Optical detector for measuring respective phases of multiple beams apparatus and method

    公开(公告)号:US09945731B1

    公开(公告)日:2018-04-17

    申请号:US14596825

    申请日:2015-01-14

    Abstract: A system includes a source of laser beams forming an array, a source of a reference laser beam, and an optical detector for measuring respective phase differences between the array laser beams and the reference laser beam. The system includes a mask, having apertures with a shape, size and position identical to a shape, size and position of the array laser beams, and positioned in the reference laser beam to form respective beams of the reference laser beam corresponding to the beams from the array laser beams. A phase modulator phase modulates respective beams of one of (a) the array laser beams and (b) the beams of the reference laser from the mask. A photodetector receives the respective array laser beams and the corresponding reference laser beams from the mask to generate a composite signal. Processing circuitry is responsive to the composite signal for generating respective signals representing the phase differences of the individual laser beams from the reference laser beam.

    Interferometer for measuring optical phase differences
    3.
    发明授权
    Interferometer for measuring optical phase differences 失效
    用于测量光学相位差的干涉仪

    公开(公告)号:US4872755A

    公开(公告)日:1989-10-10

    申请号:US164790

    申请日:1988-03-07

    Applicant: Michael Kuchel

    Inventor: Michael Kuchel

    Abstract: For generating several interferograms which differ from each other in the relative phase position between the interfering partial beams, a light source is utilized having a coherence length less than the optical path difference between the two component beams in the measuring path of the interferometer. Furthermore, at least one optical delay device is provided which splits the beam into two component beams and which generates an optical path difference between these component beams which is approximately the same as the optical path difference of the partial beams in the measuring path of the interferometer. Thereafter, the delay device again unites the component beams congruently.

    Abstract translation: 为了在干涉分光束之间的相对相位位置中产生彼此不同的几个干涉图,利用了具有小于干涉仪的测量路径中的两个分量光束之间的光程差的相干长度的光源。 此外,提供至少一个光学延迟装置,其将光束分成两个分量光束,并且在这些分量光束之间产生与干涉仪的测量路径中的部分光束的光程差大致相同的光程差 。 此后,延迟装置再次将分量光束一并整合。

    High speed/low light wavefront sensor system
    4.
    依法登记的发明
    High speed/low light wavefront sensor system 失效
    高速/低光波前传感器系统

    公开(公告)号:USH615H

    公开(公告)日:1989-04-04

    申请号:US146891

    申请日:1988-01-22

    CPC classification number: G01J9/00 G01J2009/0249

    Abstract: A scalable, low light, high speed wavefront sensor system is disclosed for real time sensing of optical wavefronts using: a gateable image intensifier tube (GIIT), a monolithic lenslet array (MLM), a custom high speed switched silicon detector array, high speed analog/digital processing components, which are microprogrammed with signal processing algorithms. The incoming wavefront is reimaged by foreoptics, then divided into multiple subapertures by the use of the MLM. The MLM forms N.times.M target images which are intensified and transferred to a detector array in which the centroid of each target image on the pixels of the detector array define the local tilt aberration of the wavefront in each subaperture. This local tilt in each subaperture is calculated with microcoded implemented algorithms using real time processing electronics. By combining the local tilt in each subaperture with wavefront reconstruction techniques, the conjugate phase map of the original wavefront can be produced for adaptive optic applications. In order to sense a desired wavefront, the "time of arrival" and flux of the incoming beam can be controlled by the processor via the time and duration of the signal to the GIIT.

    Multiple control frequency phase modulator in phase modulated
interferometer precision distance measuring system
    5.
    发明授权
    Multiple control frequency phase modulator in phase modulated interferometer precision distance measuring system 失效
    相位调制干涉仪精密测距系统中的多控制频率相位调制器

    公开(公告)号:US5459571A

    公开(公告)日:1995-10-17

    申请号:US189931

    申请日:1994-02-01

    Abstract: A phase-modulated interferometer has improved control and signal processing. Superimposition signals capable of evaluation in a phase-modulated interferometer without a complicated sawtooth control of the phase modulator are attained, in that two sinusoidal control signals which have modulation frequencies (.omega..sub.1, .omega..sub.2) and are rigidly coupled with respect to phase and frequency are applied to the known phase modulator and a cosine signal which is used in a conventional manner for evaluating the phase displacement is filtered of the superimposition signal generated in the interferometer by an electronic bandpass filter. At the filter frequency (.omega..sub.F) of the bandpass filter, an odd-number harmonic and an even-number harmonic of the two modulation frequencies (.omega..sub.1, .omega..sub.2) have the same frequency, when the amplitudes (.phi..sub.1, .phi..sub.2) of the control signals satisfy the condition for the suitable operating point of the phase modulator. The improvement has application to phase-modulated interferometers, in particular, for precision distance measuring devices, preferably by the heterodyne evaluating method.

    Abstract translation: 相位调制干涉仪具有改进的控制和信号处理。 获得能够在相位调制干涉仪中进行评估的叠加信号,无需对相位调制器进行复杂的锯齿控制,因为具有调制频率(ω1,ω2)并相对于相位和频率刚性耦合的两个正弦控制信号 应用于已知的相位调制器,并且以传统方式用于评估相位位移的余弦信号通过电子带通滤波器对在干涉仪中产生的叠加信号进行滤波。 在带通滤波器的滤波器频率(ω-F)下,两个调制频率(ω1,ω2)的奇数谐波和偶数谐波具有相同的频率,当幅度(phi 1,phi 2 )的控制信号满足相位调制器的合适工作点的条件。 该改进适用于相位调制干涉仪,特别是用于精密距离测量装置,优选地通过外差评估方法。

    Method and apparatus for phase evaluation of pattern images used in
optical measurement
    6.
    发明授权
    Method and apparatus for phase evaluation of pattern images used in optical measurement 失效
    用于光学测量中的图案图像的相位评估的方法和装置

    公开(公告)号:US5361312A

    公开(公告)日:1994-11-01

    申请号:US44105

    申请日:1993-04-08

    Applicant: Michael Kuchel

    Inventor: Michael Kuchel

    CPC classification number: G01J9/02 G01J2009/0249

    Abstract: The invention relates to measuring a phase-modulated signal 5. The signal is measured along at least five different steps (P1-P5) corresponding to preselected phase angles of the carrier wave 4. From the associated sets of measured values, at least three sets of measured values are formulated in a manner that from each of the sets a phase value [.phi..sub.i =arctan (Z.sub.i /N.sub.i) where i is equal to or greater than 3] can be calculated. The same correct phase value is computed based upon these three sets for a signal with the frequency of the carrier wave. The essence of the invention is finding that linear combinations of a.sub.i Z.sub.i and a.sub.i N.sub.i can be used for the computation of an accurate phase measurement where the factors a.sub.i are selected so that the phase error, as a function of the preselected phase steps, has at least three zero positions among the measured phase steps (P1-P5). As a result, the systemic errors that normally accompany phase measuring are significantly reduced. The invention is particularly suitable for the evaluation of bar pattern images and multiple-bar pattern images.

    Abstract translation: 本发明涉及测量相位调制信号5.该信号沿对应于载波4的预选相位角的至少五个不同步骤(P1-P5)被测量。从相关联的测量值集合,至少三组 测量值的配置方式是从每个组中可以计算出其中i等于或大于3的相位值[phi = arctan(Zi / Ni)]。 对于具有载波频率的信号,基于这三组来计算相同的正确相位值。 本发明的实质是发现aiZi和aiNi的线性组合可用于计算精确相位测量,其中选择因子ai,使得作为预选相位步长的函数的相位误差具有至少三个 测量相位步长之间的零位置(P1-P5)。 因此,通常伴随相位测量的系统误差显着降低。 本发明特别适合于条形图案和多条图案图像的评估。

    Real-time wavefront sensor for coherent wavefront characterization
    7.
    发明授权
    Real-time wavefront sensor for coherent wavefront characterization 失效
    用于相干波前表征的实时波前传感器

    公开(公告)号:US4935614A

    公开(公告)日:1990-06-19

    申请号:US333637

    申请日:1989-04-05

    CPC classification number: G01J9/02 G01J2009/0249

    Abstract: The present invention is a two beam, double pass, phase shifting interferometric system for characterizing the phase profile of a radiation path. In the preferred form of the invention, a monochromatic beam is split into a reference beam and a test path beam. The test path beam is directed toward a fixed reflector which in turn directs that beam to the image sensor with a fixed length in the direction of propagation. The reference beam is directed to a movable reflector which directs that beam also to the image sensor, while introducing phase modulation. The system provides a measure of phase offset introduced into the reference beam at times of minimum or maximum intensity as measured by each photo detector in the image sensor, as the phase modulation of the reference beam is stepped over one complete wavelength. The phase profile of the test path is constructed using the accurate representation of the modulating refelector's position at the measured minimum or maximum intensity and the number of discontinuities in the phase offset data at each element's location.

    Abstract translation: 本发明是用于表征辐射路径的相位分布的双光束双通相移干涉仪系统。 在本发明的优选形式中,单色光束被分成参考光束和测试光束光束。 测试路径光束指向固定反射器,固定的反射器又将该光束以传播方向上的固定长度引导到图像传感器。 在引入相位调制的同时,参考光束被引导到可移动反射器,其将该光束引导到图像传感器。 该系统提供在由图像传感器中的每个光电检测器测量的最小或最大强度的时候引入到参考光束中的相位偏移的量度,因为参考光束的相位调制是跨越一个完整的波长。 使用测量的最小或最大强度处的调制反馈器位置的精确表示和每个元件位置处的相位偏移数据中的不连续数量构建测试路径的相位曲线。

    Imaging coherent radiometer
    8.
    发明授权
    Imaging coherent radiometer 失效
    成像相干辐射计

    公开(公告)号:US4735507A

    公开(公告)日:1988-04-05

    申请号:US884694

    申请日:1986-07-11

    Abstract: An imaging coherent radiometer for detecting and determining the location and wavelength of coherent radiation or coherent lack of radiation in the presence of non-coherent ambient radiation. The apparatus includes an unequal path interferometer which divides incoming radiation containing coherent and non-coherent radiation into a first beam path and a second beam path through which a first beam and a second beam, respectively, travel. The optical path length difference between the first beam path and the second beam path are greater than the coherence length of the non-coherent radiation, but substantially less than the coherence length of the coherent radiation or coherent lack of radiation. Modulation means are provided to cause a predetermined difference in the optical frequencies between the first beam and the second beam proportional to a modulation signal. The first and second beams are then recombined into a recombined beam. Detecting means are provided to detect the interference of the first and second beams across the entire wavefront of the recombined beam, and over the entire image of the scene being viewed. Processing means detect and determine the location and wavelength of coherent radiation or coherent lack of radiation in the scene being viewed by the apparatus. This information can then be visually displayed. Additional processing means to respond to specific coherent wavelengths or wavelength sets.

    Abstract translation: 一种成像相干辐射计,用于在存在非相干环境辐射的情况下检测和确定相干辐射的位置和波长或相干缺乏辐射。 该装置包括不等径干涉仪,其将包含相干和非相干辐射的入射辐射分成第一光束路径和第二光束路径,第一光束和第二光束分别通过第二光束路径行进。 第一光束路径和第二光束路径之间的光程长度差大于非相干辐射的相干长度,但是基本上小于相干辐射的相干长度或相干缺乏辐射。 提供调制装置以使得与调制信号成比例的第一光束和第二光束之间的光学频率的预定差异。 然后将第一和第二光束重新组合成重组光束。 提供检测装置以检测第一和第二光束在重组光束的整个波前的干涉,以及在正在观看的场景的整个图像上。 处理装置检测并确定由装置观察到的场景中相干辐射的位置和波长或相干的辐射干扰。 然后可以直观地显示该信息。 对特定相干波长或波长集合进行响应的附加处理装置。

    Conformal imaging vibrometer using adaptive optics with scene-based wave-front sensing

    公开(公告)号:US20230175893A1

    公开(公告)日:2023-06-08

    申请号:US17544877

    申请日:2021-12-08

    CPC classification number: G01J9/04 G01J9/02 G01J2009/0249 G01J2009/0269

    Abstract: Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.

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