公开(公告)号：US5684592A

公开(公告)日：1997-11-04

申请号：US481673

申请日：1995-06-07

申请人： Phillip V. Mitchell ,  David M. Pepper ,  Thomas R. O'Meara ,  Marvin B. Klein ,  Stephen W. McCahon ,  Gilmore J. Dunning

发明人： Phillip V. Mitchell ,  David M. Pepper ,  Thomas R. O'Meara ,  Marvin B. Klein ,  Stephen W. McCahon ,  Gilmore J. Dunning

IPC分类号： G01H9/00 ,  G01B9/02

CPC分类号： G01H9/00

摘要： An ultrasound detection system that is relatively insensitive to rough workpiece surfaces, suppresses low frequency noise, and provides high sensitivity without the need for active stabilization. An optical probe beam is reflected and phase modulated by a workpiece surface that is being vibrated by ultrasound. A time-delay interferometer optically interferes the phase modulated probe beam with a time-delayed replica of itself. The optical interference generates optical interference fringes that move in accordance with the workpiece surface velocity. The interference fringes are detected by a non-steady-state photo-electromotive-force (NSS-photo-EMF) detector that generates an output signal when the frequency of fringe motion exceeds a predetermined threshold.

摘要翻译： 对粗糙的工件表面相对不敏感的超声波检测系统抑制低频噪声，并提供高灵敏度，而不需要主动稳定。 光学探针光束被被超声振动的工件表面反射和相位调制。 时间延迟干涉仪通过自身的延时复制光学干涉相位调制探测光束。 光学干涉产生根据工件表面速度移动的光学干涉条纹。 通过非稳态光电动势（NSS-photo-EMF）检测器检测干涉条纹，当检测条纹运动频率超过预定阈值时，产生输出信号。

公开(公告)号：US5585921A

公开(公告)日：1996-12-17

申请号：US404660

申请日：1995-03-15

申请人： David M. Pepper ,  Thomas R. O'Meara ,  Phillip V. Mitchell ,  Gilmore J. Dunning ,  Marvin B. Klein

发明人： David M. Pepper ,  Thomas R. O'Meara ,  Phillip V. Mitchell ,  Gilmore J. Dunning ,  Marvin B. Klein

IPC分类号： G01N29/07 ,  G01N29/24 ,  G01B9/02

CPC分类号： G01N29/075 ,  G01N29/2418 ,  G01N2291/0422 ,  G01N2291/0423 ,  G01N2291/0427

摘要： A laser-ultrasonic inspection system is provided for on-line and off-line inspection of a workpiece. The system utilizes an optical acoustic wave generation and detection system with relatively high spatial resolution and which appreciably reduces the effects of parasitic acoustic coupling. An array of acoustic waves are generated in the workpiece by a short pulse optical transmitter bee with a beam geometry that is tailored to focus the acoustic waves at an inspection site in the workpiece. The acoustic waves that probe the inspection site are then detected by reflecting an optical read-out beam from a surface of the workpiece and optically interfering it with an optical reference beam. The geometry of the optical read-out beam is chosen such that the read-out beam only detects the acoustic waves that arrive from the inspection site (acoustic waves that arrive from other parasitic acoustic sources are out of phase with respect to each other and cancel out). A wavefront compensation system improves acoustic clutter rejection and also improves the signal-to-noise by compensating for phase and amplitude aberrations induced on the optical read-out beam by the optically rough surface of the workpiece.

摘要翻译： 提供了一种激光超声波检测系统，用于在线和离线检查工件。 该系统利用具有相对较高空间分辨率的光声波产生和检测系统，并明显减少了寄生声耦合的影响。 通过短脉冲光发射器蜂在工件中产生声波阵列，其具有适于将声波聚焦在工件的检查位置处的光束几何形状。 然后通过从工件的表面反射光学读出光束并用光学参考光学光学干涉来检测探测检查部位的声波。 选择光读出光束的几何形状，使得读出光束仅检测从检查位置到达的声波（从其他寄生声源到达的声波相对于彼此异相并取消 出）。 波前补偿系统改善了声杂波抑制，并且还通过补偿由工件的光学粗糙表面在光学读出光束上感生的相位和幅度像差来改善信噪比。

公开(公告)号：US5909279A

公开(公告)日：1999-06-01

申请号：US820665

申请日：1997-03-17

申请人： David M. Pepper ,  Gilmore J. Dunning ,  Thomas R. O'Meara

发明人： David M. Pepper ,  Gilmore J. Dunning ,  Thomas R. O'Meara

IPC分类号： G01H9/00 ,  G01B9/02

CPC分类号： G01H9/006

摘要： A dual time delay interferometer (TDI) enables remote sensing of phase modulated information, such as the detection of ultrasonic vibrations from highly diffuse surfaces, preferably in the range from about 10 kHz to 100 MHZ or more. The system can also be configured in a transceive mode with a dual pass through a single TDI, which is well suited to optical communications. A non-steady-state photo-electromotive-force detector tracks the movement of interference fringes (whose position shifts as the surface vibrates), rather than their absolute position. A phased array of the sensors can be used for enhanced imaging applications requiring better signal/noise ratios, or alternatively, when lower power optical sources are employed.

摘要翻译： 双时间延迟干涉仪（TDI）能够远程感测相位调制信息，例如从高度漫射表面检测超声波振动，优选在约10kHz至100MHz或更高的范围内。 该系统也可以配置成一个双通道通过单个TDI的收发模式，这非常适合于光通信。 非稳态光电动势检测器跟踪干涉条纹（其表面振动时的位置偏移）的运动，而不是它们的绝对位置。 传感器的相控阵列可用于需要更好信号/噪声比的增强成像应用，或者当采用较低功率的光源时。

公开(公告)号：US5717516A

公开(公告)日：1998-02-10

申请号：US825835

申请日：1997-04-04

申请人： Marvin B. Klein ,  David M. Pepper ,  Ronald R. Stephens ,  Thomas R. O'Meara ,  David Welch ,  Robert J. Lang ,  Jack L. Feinberg ,  Stuart MacCormack

发明人： Marvin B. Klein ,  David M. Pepper ,  Ronald R. Stephens ,  Thomas R. O'Meara ,  David Welch ,  Robert J. Lang ,  Jack L. Feinberg ,  Stuart MacCormack

IPC分类号： G02F1/39 ,  H01S3/00 ,  G02B6/26

CPC分类号： G02F1/397

摘要： An optical amplification system directs a diffraction-limited signal beam through a series of approximately 90.degree. crossings with a number of non-diffraction-limited pump beams in a photorefractive medium. All of the beams are s-polarized, resulting in an energy transfer from the pumps to the signal beam while leaving the signal beam diffraction-limited. The photorefractive medium is preferably a series of BaTiO.sub.3 :Rh crystals that receive the pump and signal beams through orthogonal faces, with their C-axes at approximately 45.degree. to both beams. A binary tree optical distribution network is used to minimize waveguide splits in forming a large number of pump beams. The outputs of several amplification modules are combined into a single output beam using adaptive optics, with the outputs from the different modules phase matched to each other by diverting two minor portions of the combined beam, partially overlapping the diverted beams and adjusting the amplification module phases to cancel phase differentials between the overlapped portions. Similarly, sets of combined and phase-matched beams can be combined with each other (again using adaptive optics) to generate still higher powers using a super module approach.

摘要翻译： 光学放大系统通过在光折射介质中的许多非衍射受限的泵浦光束将衍射受限的信号光束引导通过一系列大约90°的交叉。 所有的光束都是s偏振的，从而导致从泵到信号光束的能量传递，同时保持信号光束衍射受限。 光折射介质优选是一系列BaTiO 3：Rh晶体，其通过正交面接收泵浦和信号光束，其C轴与两个波束大约45°。 二叉树光分配网络用于最小化形成大量泵浦波束的波导分裂。 使用自适应光学器件将多个放大模块的输出组合成单个输出光束，来自不同模块的输出通过转移组合光束的两个次要部分相互匹配，部分地与转向光束重叠并且调整放大模块相位 以消除重叠部分之间的相位差。 类似地，组合和相位匹配波束的组可以彼此组合（再次使用自适应光学器件）以使用超级模块方法来产生更高的功率。

公开(公告)号：US5546187A

公开(公告)日：1996-08-13

申请号：US404778

申请日：1995-03-15

申请人： David M. Pepper ,  Thomas R. O'Meara ,  Phillip V. Mitchell

发明人： David M. Pepper ,  Thomas R. O'Meara ,  Phillip V. Mitchell

IPC分类号： G01D5/48 ,  G01H9/00 ,  G01B9/02

CPC分类号： G01D5/48 ,  G01H9/002

摘要： An optical self-referencing ultrasonic receiver for detecting ultrasonic waves removes wavefront distortions imparted on the optical beams by diffusely reflecting readout surfaces or other sources, compensates for noise induced phase errors on the readout beam, compensates for amplitude noise present on the readout beam, substantially matches the wavefronts of the readout and reference beams, is capable of operating in a heterodyne mode and is self-aligning. In one embodiment, ultrasonic waves are measured by directing a signal beam and a reference beam to a surface of the workpiece so that the signal beam reflects off an area that is being vibrated by the ultrasonic waves, and the reference beam reflects off a different area of the surface. The signal beam gets phase modulated by the ultrasonic wave induced vibrations and also by other noise induced vibrations. The reference beam only gets phase modulated by the noise induced vibrations. The phase modulated signal and reference beams are directed to a wavefront compensator that overlaps the beams, substantially matches their wavefronts and removes wavefront distortions without altering their respective optical phases. The wavefront compensated beams are directed to a coherent detector whose output signal has a phase shift which corresponds to the difference between the optical phase shift on the signal beam (due to ultrasonic wave vibrations and noise vibrations) and the optical phase shift on the reference beam (due to noise vibrations only). Thus, noise induce vibrations common to both beams are canceled out.

摘要翻译： 用于检测超声波的光学自参考超声波接收器通过漫反射读出表面或其他源去除在光束上的波前失真，补偿读出光束上的噪声感应相位误差，补偿存在于读出光束上的振幅噪声，基本上 匹配读出和参考光束的波前，能够以外差模式工作并且是自对准的。 在一个实施例中，通过将信号光束和参考光束引导到工件的表面来测量超声波，使得信号光束从由超声波振动的区域反射，并且参考光束反射出不同的区域 的表面。 信号光束由超声波引起的振动以及其他噪声引起的振动相位调制。 参考光束仅被噪声引起的振动相位调制。 相位调制信号和参考光束被引导到与波束重叠的波前补偿器，基本上匹配它们的波阵面并去除波阵面失真而不改变它们各自的光学相位。 波前补偿光束被引导到相干检测器，其输出信号具有对应于信号光束上的光学相移（由于超声波振动和噪声振动）与参考光束之间的光学相移之间的差异的相移 （仅由于噪音振动）。 因此，消除两个光束共同的噪声诱发振动。

公开(公告)号：US5396364A

公开(公告)日：1995-03-07

申请号：US969686

申请日：1992-10-30

申请人： Thomas R. O'Meara ,  Phillip V. Mitchell

发明人： Thomas R. O'Meara ,  Phillip V. Mitchell

IPC分类号： G02B26/06 ,  G02F1/29

CPC分类号： G02B26/06

摘要： A spatial light modulator that is particularly suited for adaptive optics systems includes a charge transfer plate in which accumulated charge is continuously drained from the charge transfer pins, allowing the modulator to be operated in a continuous mode with a very rapid speed of response. Charge is drained through RC circuits that consist of inherent or discrete resistors and inherent capacitances associated with the pins. A lenslet array focuses an input beam onto the curvature bases of pixels in an associated deformable mirror, thereby obtaining reflections from the mirror with generally flat wavefronts and a greatly increased optical efficiency; a companion lenslet array and mirror combination outside the SLM compensates pixel inversions produced by the first lenslet array. The charge transfer plate is made gas impervious by fabricating the charge transfer pins as thermally migrated conductors, and conductive electric shield pins are preferably also provided to shield the charge transfer pins from each other.

摘要翻译： 特别适用于自适应光学系统的空间光调制器包括电荷转移板，其中累积电荷从电荷传输引脚连续排出，允许调制器以非常快的响应速度在连续模式下操作。 电荷通过由固定或分立电阻组成的RC电路和与引脚相关的固有电容来排除。 小透镜阵列将输入光束聚焦在相关联的可变形反射镜中的像素的曲率基底上，从而从具有大致平坦波前的反射镜获得反射并大大提高光学效率; 在SLM外部的伴侣小透镜阵列和镜组合补偿由第一小透镜阵列产生的像素反转。 电荷转移板通过制造作为热迁移导体的电荷转移引脚而被制成气体不可渗透的，并且优选还提供导电电屏蔽引脚以将电荷传输引脚彼此屏蔽。

公开(公告)号：US07262861B1

公开(公告)日：2007-08-28

申请号：US10852782

申请日：2004-05-24

申请人： David M. Pepper ,  Thomas R. O'Meara

发明人： David M. Pepper ,  Thomas R. O'Meara

IPC分类号： G01B11/02

CPC分类号： G01B17/02 ,  G01B11/06 ,  G01N21/1702 ,  G01N29/043 ,  G01N29/2418 ,  G01N2291/02827 ,  G01N2291/02854 ,  G01N2291/0421

摘要： A laser ultrasonic inspection apparatus and method which enables remote sensing of thickness, hardness, temperature and/or internal defect detection is disclosed. A laser generator impinges a workpiece with light for generating a thermo-elastic acoustic reaction in a workpiece. A probe laser impinges the workpiece with an annularly-shaped probe light for interaction with the acoustic signal in the workpiece resulting in a modulated return beam. A photodetector having a sensitive region for detecting an annularly-shaped fringe pattern generated by an interaction of a reference signal and with the modulated return beam at said sensitive region.

摘要翻译： 公开了能够远程检测厚度，硬度，温度和/或内部缺陷检测的激光超声波检查装置和方法。 激光发生器用工件照射工件以在工件中产生热弹性声反应。 探头激光器用环形探针光照射工件，以与工件中的声信号相互作用，从而产生调制的返回光束。 一种光电检测器，具有用于检测通过参考信号的相互作用产生的环形条状图案的敏感区域和在所述敏感区域处的调制返回光束。

公开(公告)号：US4833314A

公开(公告)日：1989-05-23

申请号：US236343

申请日：1988-08-22

申请人： David M. Pepper ,  Thomas R. O'Meara

发明人： David M. Pepper ,  Thomas R. O'Meara

IPC分类号： G01J9/02 ,  G02F1/13 ,  G02F1/1343

CPC分类号： G02F1/134309 ,  G01J9/02 ,  G02F1/1313

摘要： An electro-optical device (10) is used to alter characteristics of a light beam passing through it. In a particularly preferred embodiment, the device (10) is used as a phase stop having a dynamically variable aperture whose size is defined by the selected application of an electrical potential across one or more concentric, transparent ring-like electrodes (13, 14, 16 and 18). The electro-optical device (10) finds particular utility in a common-path interferometer (40) where fringe visibility is optimized by using suitable servo-electronics (56) to select an appropriate aperture size for the phase stop (10).

摘要翻译： 电光装置（10）用于改变通过它的光束的特性。 在特别优选的实施例中，装置（10）用作具有动态可变孔径的相位停止器，其尺寸由所选择的跨越一个或多个同心的透明环状电极（13,14， 16和18）。 电光装置（10）在公共路径干涉仪（40）中具有特别的用途，其中通过使用合适的伺服电子设备（56）来选择相位停止（10）的适当孔径尺寸来优化边缘可见度。

公开(公告)号：US5048935A

公开(公告)日：1991-09-17

申请号：US947575

申请日：1986-12-24

申请人： Uzi Efron ,  Bernard H. Soffer ,  Richard C. Lind ,  David M. Pepper ,  Thomas R. O'Meara

发明人： Uzi Efron ,  Bernard H. Soffer ,  Richard C. Lind ,  David M. Pepper ,  Thomas R. O'Meara

IPC分类号： G01J9/00 ,  G02B26/06

CPC分类号： G03H1/0005 ,  G01J9/00 ,  G02B26/06 ,  G03H1/2294 ,  G03H2001/0066 ,  G03H2225/32

摘要： Apparatus for compensating for inherent distortions in a modified liquid crystal light valve used in an integrated wavefront sensing and wavefront control system for laser optics. A main wavefront sensing and control system utilizes a liquid crystal light valve selected for response speed but having inherent surface non-linearities. A beam from an auxiliary laser is intermittently applied, while the main laser is blocked, to both the fast response LCLV of the main system and to a slower response LCLV of an associated correction system. The second LCLV system corrects for the non-linearities in the surface of the first LCLV and then maintains the stored correction signal for a decay interval which corresponds to several response times of the main LCLV, thus permitting the main LCLV system to perform fast correction of atmospheric aberrations in the laser beam wavefront unaffected by inherent surface non-linearities.

摘要翻译： 用于补偿在用于激光光学的集成波前感测和波前控制系统中使用的改进的液晶光阀中的固有失真的装置。 主波前感测和控制系统利用了选择响应速度但具有固有表面非线性的液晶光阀。 来自辅助激光器的光束在主激光器被阻挡的同时被间歇地施加到主系统的快速响应LCLV和相关校正系统的较慢响应LCLV。 第二LCLV系统校正第一LCLV的表面中的非线性，然后将存储的校正信号维持在对应于主LCLV的几个响应时间的衰减间隔，从而允许主LCLV系统执行快速校正 激光束波前的大气像差不受固有表面非线性的影响。

公开(公告)号：US06285514B1

公开(公告)日：2001-09-04

申请号：US09564623

申请日：2000-05-04

申请人： Thomas R. O'Meara ,  David M. Pepper

发明人： Thomas R. O'Meara ,  David M. Pepper

IPC分类号： G02B310

CPC分类号： G01D5/26 ,  G01D5/266 ,  G01H9/00 ,  G01N29/2418

摘要： A lens for angularly overlapping a central portion of an optical beam with an outer portion of the beam is disclosed. The lens comprises a lens body having an optical axis, a rear surface on said lens body for receiving an optical beam, and a front surface on said lens body that includes inner and outer portions. The outer surface portion is inclined at a greater angle from the optical axis than the inner surface portion so that the outer portion of a beam transmitted through the lens from its rear surface to said outer surface portion is refracted by a lesser angle than an inner portion of the beam which reaches said inner surface portion. The inner and outer lens surface portions also have an angle between them which causes said inner and outer beam portions to converge and overlap at a non-zero angle forward of the lens, wherein the angle of the outer beam portion to the optical axis is selected to superimpose the inner beam portion and outer beam portion such that optical interference fringe patterns are formed.

摘要翻译： 公开了一种用于将光束的中心部分与梁的外部部分成角度地重叠的透镜。 透镜包括具有光轴的透镜体，用于接收光束的所述透镜主体上的后表面，以及包括内部和外部的所述透镜主体上的前表面。 外表面部分比光轴以比内表面部分更大的角度倾斜，使得透过透镜的光束从其后表面到外表面部分的外部部分被折射比内部部分更小的角度 到达所述内表面部分的光束。 内透镜表面部分和外透镜表面部分之间也具有一个角度，这使得所述内光束部分和外光束部分在透镜前方非零角度会聚和重叠，其中外光束部分对光轴的角度被选择 以将内光束部分和外光束部分叠加以形成光学干涉条纹图案。