公开(公告)号：US06717680B1

公开(公告)日：2004-04-06

申请号：US10144527

申请日：2002-05-13

Applicant: Michael Kuchel ,  Leslie L. Deck

Inventor： Michael Kuchel ,  Leslie L. Deck

IPC: G01B902

CPC classification number: G01B11/306 ,  G01B9/02002 ,  G01B9/02004 ,  G01B9/02057 ,  G01B9/02064 ,  G01B11/2441 ,  G01B2290/70

Abstract: The invention extends and improves the basic technique of phase-shifting interferometry by minimizing the measurement errors introduced by additional unwanted reflections from surfaces and surface defects far from the surface of interest. The inventive phase shifting interferometer includes at least two independent phase shifters. The two phase shifters operate cooperatively to produce a particular desired cavity interference modulation frequency while the modulation frequency of interference produced from other sources is significantly altered.

Abstract translation: 本发明通过最小化从远离感兴趣的表面的表面和表面缺陷的附加不需要的反射引入的测量误差来扩展和改进相移干涉测量的基本技术。 本发明的相移干涉仪包括至少两个独立的移相器。 两个移相器协同工作以产生特定的期望腔干扰调制频率，而从其它源产生的干扰的调制频率被显着地改变。

公开(公告)号：US5135309A

公开(公告)日：1992-08-04

申请号：US666247

申请日：1991-03-08

Applicant: Michael Kuchel ,  Albrecht Hof

Inventor： Michael Kuchel ,  Albrecht Hof

IPC: G01B11/24 ,  G01B11/25 ,  G01C3/06

CPC classification number: G06T7/0057 ,  G01B11/2531

Abstract: Several bar patterns are projected in sequence on the object (O) to be measured by time-division multiplexing, and images of the bar patterns are recorded by a camera (K). The phases of each bar pattern, as distorted by the object, are calculated for preselected image points by a computer connected with the camera. For each image point, the calculated phases for one of said bar patterns are compared to the phases calculated for at least one other of said bar patterns, thereby producing a beat frequency which can be used to determine height measurements in the direction of the camera axis (z). In order to increase the range of the height measurements, at least two beat frequencies of quite different effective wavelengths are generated and evaluated. Different systems are disclosed for generating the different beat frequencies. In one embodiment, the bar patterns are projected by three different projectors (P.sub.1, P.sub.2, P.sub.3) which are inclined at different angles relative to each other (.alpha..sub.1, .alpha..sub.2). In a second embodiment, only two projectors are used, but each projector has two gratings, the respective periods of which differ from each other only slightly.

Abstract translation: 通过时分多路复用将待测物体（O）上的几个条形图案依次投影，并通过照相机（K）记录条形图案。 通过与相机连接的计算机为预选图像点计算每个条形图案的由对象扭曲的相位。 对于每个图像点，将所述条形图案中的一个的计算的相位与针对所述条形图案中的至少另一个计算的相位进行比较，从而产生拍频，其可用于确定相机轴方向上的高度测量值 （z）。 为了增加高度测量的范围，产生和评估至少两个完全不同有效波长的拍频。 公开了用于产生不同拍频的不同系统。 在一个实施例中，条形图案由相对于彼此以不同角度（α1，α2）倾斜的三个不同的投影仪（P1，P2，P3）投射。 在第二实施例中，仅使用两个投影仪，但是每个投影仪具有两个光栅，其各自的周期彼此稍微不同。

公开(公告)号：US20080068613A1

公开(公告)日：2008-03-20

申请号：US11901010

申请日：2007-09-14

Applicant: Michael Kuchel

Inventor： Michael Kuchel

IPC: G01B11/02

CPC classification number: G01B11/2441 ,  G01M11/025 ,  G01M11/0271

Abstract: Interferometric scanning method(s) and apparatus for measuring test optics having aspherical surfaces including those with large departures from spherical. A reference wavefront is generated from a known origin along a scanning axis. A test optic is aligned on the scanning axis and selectively moved along it relative to the known origin so that the reference wavefront intersects the test optic at the apex of the aspherical surface and at one or more radial positions where the reference wavefront and the aspheric surface intersect at points of common tangency (“zones”) to generate interferograms containing phase information about the differences in optical path length between the center of the test optic and the one or more radial positions. The interferograms are imaged onto a detector to provide an electronic signal carrying the phase information. The axial distance, ν, by which the test optic is moved with respect to the origin is interferometrically measured, and the detector pixel height corresponding to where the reference wavefront and test surface slopes match for each scan position is determined. The angles, α, of the actual normal to the surface of points Q at each “zone” are determined against the scan or z-axis. Using the angles, α, the coordinates z and h of the aspheric surface are determined at common points of tangency and at their vicinity with αmin≦α≦αmax, where αmin and αmax correspond to detector pixels heights where the fringe density in the interferogram is still low. The results can be reported as a departure from the design or in absolute terms.

Abstract translation: 用于测量具有非球面表面的测试光学元件的干涉测量扫描方法和装置，包括具有大的偏离球面的那些。 沿着扫描轴从已知原点生成参考波前。 测试光学元件在扫描轴上对准并且相对于已知原点被选择性地移动，使得参考波前与非球面的顶点处的测试光学器件相交，并且在一个或多个径向位置处，其中参考波前和非球面 在公共切线（“区域”）的点处相交以产生干涉图，其包含关于测试光学元件的中心与一个或多个径向位置之间的光程长度差的相位信息。 干涉图被成像到检测器上以提供携带相位信息的电子信号。 测量光学元件相对于原点移动的轴向距离nu被干涉测量，并且确定对应于每个扫描位置的参考波前和测试表面斜率匹配的检测器像素高度。 针对扫描或z轴确定在每个“区域”处的点Q的表面的实际法线的角度α。 使用角度α，非球面的坐标z和h在公共相切点和其附近由α分钟确定。α=α< ，其中α分钟和α最大值对应于干涉图中的边缘密度仍然较低的检测器像素高度。 结果可以报告为偏离设计或绝对值。

公开(公告)号：US07289224B2

公开(公告)日：2007-10-30

申请号：US10941631

申请日：2004-09-15

Applicant: Xavier Colonna De Lega ,  Peter J. De Groot ,  Michael Kuchel

Inventor： Xavier Colonna De Lega ,  Peter J. De Groot ,  Michael Kuchel

IPC: G01B9/02

CPC classification number: G03F7/70491 ,  G01B9/02019 ,  G01B9/02022 ,  G01B9/02084 ,  G01B9/02087 ,  G01B9/0209 ,  G01B11/0675 ,  G01B2290/30 ,  G01B2290/70 ,  G03F7/70608 ,  G03F7/70641 ,  G03F7/70775 ,  G03F9/7003 ,  G03F9/7049 ,  G03F9/7088

Abstract: An optical system includes a photolithography system, a low coherence interferometer, and a detector. The photolithography system is configured to illuminate a portion of an object with a light pattern and has a reference surface. The low coherence interferometer has a reference optical path and a measurement optical path. Light that passes along the reference optical path reflects at least once from the reference surface and light that passes along the measurement optical path reflects at least once from the object. The detector is configured to detect a low coherence interference signal including light that has passed along the reference optical path and light that has passed along the measurement optical path. The low coherence interference signal is indicative of a spatial relationship between the reference surface and the object.

Abstract translation: 光学系统包括光刻系统，低相干干涉仪和检测器。 光刻系统被配置为用光图案照射物体的一部分并具有参考表面。 低相干干涉仪具有参考光路和测量光路。 沿着基准光路通过的光至少从参考面反射一次，并且沿测量光路通过的光从物体反射至少一次。 检测器被配置为检测包括沿着参考光路已经通过的光和沿着测量光路已经通过的光的低相干干涉信号。 低相干干涉信号指示参考表面和对象之间的空间关系。

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

IPC: G01J9/02 ,  H03D13/00 ,  G06K9/00

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。

公开(公告)号：US5054912A

公开(公告)日：1991-10-08

申请号：US609584

申请日：1990-11-06

Applicant: Michael Kuchel

Inventor： Michael Kuchel

IPC: G01C3/06 ,  G01S17/36 ,  G01S17/87

CPC classification number: G01S17/36 ,  G01S17/87

Abstract: The invention relates to an optical rangefinding device which consists of two frequency-stabilized multi-mode lasers. Two modes of each laser are superimposed so that each laser generates its own respective amplitude-modulated beam; and each beam is used, alternately, as the measuring light beam. The amplitude-modulation frequencies are selected so that the electronic detection of the two amplitude-modulated light beams, followed by electronic mixing of the individually detected signals, generates an electronic pulse train having a difference frequency which is only a fraction of the two modulation frequencies. The emitted and reflected frequencies of each of these amplitude-modulated beams are phase-compared. Each of these phase comparisons and the difference between them are used to determine distance to the target. Since phase shifts are digitally measured at the relatively low difference frequency by a digital clock rate based upon the relatively high frequency-modulated signal of one of the lasers, phase shift is determined with high accuracy. Further, the device provides measurements having a relatively accuracy which corresponds to the difference in wavelengths of the two amplitude-modulated beams which, in turn, have an accuracy corresponding to the spectral sharpness of the frequency-stabilized lasers.

Abstract translation: 本发明涉及一种由两个频率稳定的多模激光器组成的光学测距装置。 每个激光器的两种模式被叠加，使得每个激光器产生其自己的各自的幅度调制光束; 并且每个光束交替地被用作测量光束。 选择幅度调制频率，使得两个幅度调制光束的电子检测，随后是单独检测的信号的电子混合，产生具有仅两个调制频率的一部分的差分频率的电子脉冲串 。 这些幅度调制波束中的每一个的发射和反射频率被相位比较。 这些相位比较中的每一个和它们之间的差异用于确定到目标​​的距离。 由于基于相对较高频率调制的激光器之一的频率调制信号，以相对较低的差分频率以数字时钟速率对相移进行数字测量，所以以高精度确定相移。 此外，该装置提供具有对应于两个幅度调制波束的波长的相对精度的测量，这两个幅度调制波束的波长依次具有与频率稳定的激光器的频谱清晰度相对应的精度。