公开(公告)号：US4798467A

公开(公告)日：1989-01-17

申请号：US911023

申请日：1986-09-24

Applicant: Richard W. Wyeth ,  Michael A. Johnson ,  Michael A. Globig

Inventor： Richard W. Wyeth ,  Michael A. Johnson ,  Michael A. Globig

IPC: G01J9/00 ,  B01D59/34 ,  G01J9/04 ,  G01M11/00 ,  G01B9/02

CPC classification number: G01J9/04

Abstract: A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.

Abstract translation: 公开了一种外差激光瞬时频率测量系统。 该系统利用脉冲激光束与连续波激光束的外差来形成拍频信号。 拍频信号由控制器或计算机进行处理，该控制器或计算机在脉冲期间确定激光脉冲的平均频率和频率的任何变化或啁啾。

公开(公告)号：US4759628A

公开(公告)日：1988-07-26

申请号：US826341

申请日：1986-02-05

Applicant: Kimio Tatsuno ,  Yoshito Tsunoda ,  Masatoshi Ohtake ,  Keiji Kataoka ,  Seiji Yonezawa

Inventor： Kimio Tatsuno ,  Yoshito Tsunoda ,  Masatoshi Ohtake ,  Keiji Kataoka ,  Seiji Yonezawa

IPC: G01J9/02 ,  G01B9/02 ,  G01J3/45 ,  G01J9/04

CPC classification number: G01J9/04 ,  G01J3/45

Abstract: In an interferometry wherein a light beam from a light source is divided in two, one of which is used as a reference beam and the other beam is used as an inspecting beam, and the two beams are projected again on an identical plane so as to form an interference pattern; a wavelength scanning type laser diode interferometry characterized in that a laser diode is employed as the light source, and that an injection current of the laser diode is modulated thereby to scan a wavelength of the laser diode and to change an intensity distribution of the interference pattern.

Abstract translation: 在其中来自光源的光束被分成两部分的干涉测量中，其中一个用作参考光束，另一个光束用作检查光束，并且两个光束再次投射在相同的平面上，以便 形成干扰模式; 波长扫描型激光二极管干涉测量法，其特征在于使用激光二极管作为光源，并且调制激光二极管的注入电流，从而扫描激光二极管的波长并改变干涉图案的强度分布 。

公开(公告)号：US4671657A

公开(公告)日：1987-06-09

申请号：US767164

申请日：1985-08-19

Applicant: Riccardo Calvani ,  Renato Caponi ,  Francesco Cisternino

Inventor： Riccardo Calvani ,  Renato Caponi ,  Francesco Cisternino

IPC: G01J4/04 ,  G01J4/00 ,  G01J9/04 ,  G01N21/21 ,  G01B9/02

CPC classification number: G01J4/00 ,  G01J9/04

Abstract: Method and device for realtime measurement of the state of polarization at a quasi-monochromatic light beam. Two quasi-monochromatic radiations with slightly different optical frequencies are generated. A radiation is converted into a 45.degree. linearly polarized radiation, while the other presents the polarization state imposed by a body under test. In each radiation, horizontal and vertical polarization components are separated, and then recombined into two different beams comprising radiations at both frequencies, respectively polarized in the same plane. Beatings between the two components of each beam are originated and from the two electrical signals in the radiofrequency range thus obtained the information is extracted on the relative phase and the amplitude of the two components of the radiation with polarization imposed by the body under test.

Abstract translation: 用于实时测量准单色光束的偏振态的方法和装置。 产生具有稍微不同光频率的两个准单色辐射。 辐射被转换为45°线性偏振辐射，而另一种则呈现由被测体引起的极化状态。 在每个辐射中，水平和垂直偏振分量被分离，然后再组合成两个不同的波束，两个不同的波束包括两个频率的辐射，分别在同一平面上极化。 在每个光束的两个分量之间发生跳动，并且从这样获得的射频范围内的两个电信号中，信息被提取在被被测体施加的极化的辐射的相对相位和振幅上。

公开(公告)号：US4627730A

公开(公告)日：1986-12-09

申请号：US628181

申请日：1984-07-06

Applicant: Roger L. Jungerman ,  Gordon S. Kino

Inventor： Roger L. Jungerman ,  Gordon S. Kino

IPC: G01J9/04 ,  G01N21/84 ,  G01N21/95 ,  G02B21/00 ,  G01B9/02

CPC classification number: G02B21/002 ,  G01J9/04 ,  G01N21/8422 ,  G01N21/95

Abstract: A scanning optical microscope causes a collimated light beam to impinge on a Bragg cell. A high frequency signal applied to another surface of the Bragg cell modulates the impinging light beam. The output of the Bragg cell comprises two waves: a portion of the impinging light beam which passes directly through the cell or diffraction grating, and a second deflected output beam whose frequency is shifted by the frequency of the applied signal. By modifying the frequency of the applied frequency signal, the deflected beam may be scanned across the surface, while the reference beam remains in place and serves as a phase reference. By detecting the two beams reflected from the surface on a single photodetector, shifts in phase and amplitude of the deflected beam can be determined. To provide further isolation of the system from external vibration, a second input light beam is applied to the diffraction grating, the input of this second beam being in a plane which is essentially perpendicular to the direction of the scanned output beam. This input beam, after passing through the diffraction grating, will provide two further beams which impinge on the surface. These two beams, which are to serve as reference beams, should be focused on a known flat surface; alternatively, the size of these beams may be expanded so their size is very large relative to any surface feature to be detected; or as a further alternative, they may be reflected from a known stable reference surface. In either event, the surface reflection of these beams is detected at a separate photodetector; upon mixing with the scan beam, the reference can be used to detect any changes in phase and amplitude, while cancelling out variations due to changes in frequency of the modulating optical wave.

Abstract translation: 扫描光学显微镜使准直光束照射到布拉格单元上。 施加到布拉格单元的另一表面的高频信号调制入射光束。 布拉格单元的输出包括两个波：直接通过单元或衍射光栅的入射光束的一部分，以及频率偏移所施加的信号的频率的第二偏转输出波束。 通过修改施加的频率信号的频率，偏转的波束可以跨越表面进行扫描，而参考光束保持原位并用作相位参考。 通过检测在单个光电检测器上从表面反射的两个光束，可以确定偏转光束的相位和振幅偏移。 为了提供系统与外部振动的进一步隔离，第二输入光束被施加到衍射光栅，该第二光束的输入在基本上垂直于扫描的输出光束的方向的平面内。 该输入光束在通过衍射光栅之后将提供两个冲击在表面上的光束。 这两个用作参考光束的光束应该聚焦在已知的平坦表面上; 或者，这些光束的尺寸可以被扩大，使得它们的尺寸相对于待检测的任何表面特征是非常大的; 或作为另外的替代方案，它们可以从已知的稳定参考表面反射。 在任一情况下，在单独的光电检测器处检测这些光束的表面反射; 在与扫描光束混合时，可以使用参考来检测相位和振幅的任何变化，同时消除由于调制光波的频率变化引起的变化。

公开(公告)号：US4575247A

公开(公告)日：1986-03-11

申请号：US627363

申请日：1984-07-02

Applicant: Richard J. Tansey

Inventor： Richard J. Tansey

IPC: G01J1/42 ,  G01J9/02 ,  G01J9/04 ,  G01B9/02

CPC classification number: G01J9/04 ,  G01J1/4257 ,  G01J2009/0223 ,  G01J2009/0234 ,  G01J2009/0261

Abstract: A heterodyne phase-determining interferometer comprising a Smartt point diffraction interferometer (PDI) 10 in which the pinhole plate 22 is replaced by a half-wave, partially transmitting plate 22' with a pinhole 20 therein. The output beams 26 and 24 from the pinhole 20 are propagated through a frequency shifter 12 which includes a quarter-wave plate 28 whose axis is at 45.degree. to the polarization axes of the two beams 26 and 24 coming from the PDI 10, a half-wave plate 30 rotating at an angular frequency of .omega., and a linear polarizer which orients the polarization vectors of the two beams in the same direction along the propagation axis. The output of the frequency shifter 12 is a moving interference pattern consisting of alternate light and dark lines. This pattern is projected upon a phase-measuring means 14 comprising an array of photodetectors 34, 36 connected to a plurality of phase-to-voltage converters 38. There is one reference photodetector 34, the rest being test photodetectors. The reference photodetector 34 is connected to all phase-to-voltage converters 38, but each test photodetector 36 is connected to a different phase-to-voltage converter 38. The output of each converter 38 is the phase difference between the light at the point viewed by its associated test photodetector 36 and the light at the point viewed by the reference photodetector 34.

Abstract translation: 一种外差相位确定干涉仪，其包括Smartt点衍射干涉仪（PDI）10，其中针孔板22被其中具有针孔20的半波部分透射板22'代替。 来自针孔20的输出光束26和24通过一个变频器12传播，该变频器12包括一个四分之一波长的板28，该四分之一波片28的轴线相对于来自PDI 10的两个光束26和24的偏振轴为45度， 波片30以ω的角度频率旋转，以及线性偏振器，其沿着传播轴线沿相同方向定向两个光束的偏振矢量。 移频器12的输出是由交替的亮线和暗线组成的移动干涉图案。 该图案被投影在包括连接到多个相电压转换器38的光电检测器34,36的阵列的相位测量装置14上。存在一个参考光电检测器34，其余的是测试光电探测器。 参考光电检测器34连接到所有相电压转换器38，但是每个测试光电检测器36连接到不同的相电压转换器38.每个转换器38的输出是点处的光之间的相位差 通过其相关联的测试光电检测器36观察，以及由参考光电检测器34观察的点处的光。

公开(公告)号：US4491867A

公开(公告)日：1985-01-01

申请号：US421776

申请日：1982-09-23

Applicant: Jean-Pierre Huignard

Inventor： Jean-Pierre Huignard

IPC: G01J9/04 ,  G02F1/03 ,  G03H1/00

CPC classification number: G03H1/00 ,  G01J9/04 ,  G02F1/0338

Abstract: A device for the heterodyne detection of the image of targets illuminated by a laser, wherein the target reflects a wave .SIGMA..sub.1, which is amplified in an included refractive index variation medium also illuminated by a reference wave .SIGMA..sub.R derived from the laser to produce an amplified wave .SIGMA..sub.2. A portion of the wave .SIGMA..sub.1 prior to amplification is directed incident on a frequency shifter to produce frequency shifted wavefront .SIGMA..sub.10. Wavefront .SIGMA..sub.2 and the frequency-shifted wavefront .SIGMA..sub.10 are directed incident on the same partially reflection mirror to interfere with one another and the resultant beat interference wave is focused on a matrix of photodetectors and then filtered. This device has application to infrared image detection.

Abstract translation: 用于外差检测由激光照射的目标的图像的装置，其中所述目标反射波SIGMA1，所述波SIGMA 1在包括的折射率变化介质中被放大，所述折射率变化介质也被从所述激光器得到的参考波SIGMA R所照射，以产生 放大波SIGMA2。放大之前的波形SIGMA 1的一部分被引导入射到移频器上以产生频移波前SIGMA 10.波前SIGMA 2和频移波前SIGMA 10被引导入射在相同的部分反射镜 相互干扰，产生的拍频干扰波集中在光电检测器的矩阵上，然后滤波。 该设备适用于红外图像检测。

公开(公告)号：US4449825A

公开(公告)日：1984-05-22

申请号：US272520

申请日：1981-06-11

Applicant: Albert D. May

Inventor： Albert D. May

IPC: G01J9/04 ,  G01N21/23 ,  G01B9/02

CPC classification number: G01J9/04 ,  G01N21/23

Abstract: The invention provides optical measuring apparatus including a laser which is arranged to have an output of electromagnetic radiation including at least two different simultaneously-generated frequencies. This output is fed to a detector, such as an optical diode, which produces a corresponding electric signal at the difference (beat) frequency. The beat frequency, any change in the beat frequency, or any rate of change of the beat frequency can now be examined electrically to the degree of accuracy generally available in that art, usually to a much higher degree than is available in the optical or mechanical arts. The parameter to be examined may be that of an element causing the production of the beat frequency such as a birefringent material, or may be that of an element which changes the frequency in some way, such as an angular orientation of two quarter-wave plates.

Abstract translation: 本发明提供了包括激光器的光学测量装置，该激光器被布置成具有包括至少两个不同的同时产生的频率的电磁辐射的输出。 该输出被馈送到诸如光二极管的检测器，其在差（拍）频率处产生相应的电信号。 节拍频率，拍频的任何变化或拍频的任何变化率现在都可以通过该技术通常可获得的精度来进行检查，通常比光学或机械可用的程度高得多 艺术 要检查的参数可以是导致产生拍频的元件，例如双折射材料，或者可以是以某种方式改变频率的元件，例如两个四分之一波片的角取向 。

公开(公告)号：US4272193A

公开(公告)日：1981-06-09

申请号：US30044

申请日：1979-04-13

Applicant: Jay M. Eastman ,  Theodore L. Miller

Inventor： Jay M. Eastman ,  Theodore L. Miller

IPC: G01J9/04 ,  H01S3/00 ,  H05H1/22 ,  G01B9/02

CPC classification number: G21B1/23 ,  G01J9/04 ,  H01S3/0057

Abstract: The optical path lengths of a plurality of comparison laser beams directed to impinge upon a common target from different directions are compared to that of a master laser beam by using an optical heterodyne interferometric detection technique. The technique consists of frequency shifting the master laser beam and combining the master beam with a first one of the comparison laser beams to produce a time-varying heterodyne interference pattern which is detected by a photo-detector to produce an AC electrical signal indicative of the difference in the optical path lengths of the two beams which were combined. The optical path length of this first comparison laser beam is adjusted to compensate for the detected difference in the optical path lengths of the two beams. The optical path lengths of all of the comparison laser beams are made equal to the optical path length of the master laser beam by repeating the optical path length adjustment process for each of the comparison laser beams. In this manner, the comparison laser beams are synchronized or timed to arrive at the target within .+-.1.times.10.sup.-12 second of each other.

Abstract translation: 通过使用光学外差干涉测量技术将指向从不同方向撞击到公共目标的多个比较激光束的光路长度与主激光束的光路长度进行比较。 该技术包括对主激光束进行频移，并将主光束与第一个比较激光束组合以产生时变的外差干涉图案，其由光检测器检测以产生指示 组合的两个光束的光程长度的差异。 调整该第一比较激光束的光路长度以补偿两个光束的光路长度的检测差异。 通过对每个比较激光束重复光程长度调整处理，使所有比较激光束的光程长度等于主激光束的光程长度。 以这种方式，比较激光束被同步或定时以在彼此的+/- 1×10-12秒内到达目标。

公开(公告)号：US3656853A

公开(公告)日：1972-04-18

申请号：US3656853D

申请日：1969-03-10

Applicant: HEWLETT PACKARD CO

Inventor： BAGLEY ALAN S ,  CUTLER LEONARD S ,  RANDO JOSEPH F

IPC: G01B9/02 ,  G01J9/04

CPC classification number: G01B9/02007 ,  G01B9/02003 ,  G01B9/0207 ,  G01J9/04

Abstract: A portion of a first laser light beam of one optical frequency and a portion of a second laser light beam of a different optical frequency are mixed by a photoelectric device to produce an electrical reference signal having a countable intermediate frequency. Another portion of the first laser light beam traverses a fixed length optical path of an interferometer, and another portion of the second laser light beam traverses a variable length optical path of the interferometer. These other portions of the first and second laser light beams are mixed by another photoelectric device to produce an electrical information signal having the same countable intermediate frequency as the reference signal only while the optical length of the variable length optical path is not being changed. A reversible counter integrates the difference in frequency between the reference and information signals while the optical length of the variable length optical path is being changed to indicate the change in length of the variable length optical path.

Abstract translation: 一个光频率的第一激光束的一部分和不同光频的第二激光束的一部分被光电装置混合，以产生具有可计数的中频的电参考信号。 第一激光束的另一部分穿过干涉仪的固定长度光路，第二激光束的另一部分穿过干涉仪的可变长度光路。 第一和第二激光束的这些其它部分被另一个光电装置混合，以产生具有与参考信号相同的可计数中频的电信息信号，而可变长度光路的光学长度不改变。 可逆计数器在可变长度光路的光学长度被改变以指示可变长度光路的长度变化的情况下，将参考信息信号之间的频率差集成在一起。

公开(公告)号：US3428816A

公开(公告)日：1969-02-18

申请号：US3428816D

申请日：1965-03-25

Applicant: NORTH AMERICAN ROCKWELL

Inventor： JACOBS EARL D ,  QUICK WILLIAM H

IPC: G01J9/04 ,  G01N21/26

CPC classification number: G01J9/04