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21. 发明公开

EP1193483A2 Method and system for optical heterodyne detection of an optical signal 有权
标题翻译： Verfahren und System zur optischenÜberlagerungsdetektioneines optischen Signals
公开(公告)号：EP1193483A2
公开(公告)日：2002-04-03
申请号：EP01117550.2
申请日：2001-07-20
申请人： Agilent Technologies, Inc. (a Delaware corporation)
发明人： Sorin, Wayne V. , Szfraniec, Bogdan , Baney, Douglas M.
IPC分类号： G01J9/04
CPC分类号： H04B10/60 , G01J9/04 , H04B10/64
摘要： An optical heterodyne detection system in accordance with an embodiment of the invention includes two optical receivers (232 and 242) for separately measuring the power of an input signal (202) and a local oscillator signal (206) before the signals are combined. The measurements of the input signal and the local oscillator signal are then utilized by a processor (216) to enhance the heterodyne signal to noise ratio by removing the intensity noise contributed by the input signal and the local oscillator signal. By measuring portions of the input signal power and the local oscillator signal power and then subtracting out the scaled quantities from the photocurrent measurement during signal processing, the signal to noise of the heterodyne signal is improved beyond that which is accomplished by known balanced receivers.
摘要翻译：根据本发明实施例的光外差检测系统包括两个用于在信号组合之前分别测量输入信号（202）和本地振荡器信号（206）的功率的光接收器（232和242）。输入信号和本地振荡器信号的测量然后由处理器（216）利用，以通过去除由输入信号和本地振荡器信号贡献的强度噪声来增强外差信噪比。通过测量输入信号功率和本地振荡器信号功率的部分，然后在信号处理期间从光电流测量中减去量化的量，外差信号的信噪比被改进超过了已知的平衡接收机完成的信噪比。

22. 发明授权

EP0631660B1 INTERFEROMETER REQUIRING NO CRITICAL COMPONENT ALIGNMENT 失效
标题翻译：干涉，而不需要对重要部件取向
公开(公告)号：EP0631660B1
公开(公告)日：2001-08-08
申请号：EP92912164.8
申请日：1992-05-07
申请人： WANG, Charles C.P.
发明人： WANG, Charles C.P.
IPC分类号： G01B9/02 , G01J9/04
CPC分类号： G01B9/02092 , G01B9/02002
摘要： A Michealson-type self-aligning interferometer utilizes a laser (1) to produce an output beam (20) of light that is split into a signal beam (40) and a reference beam (30). The signal beam (40) is directed through a Bragg-cell (5), for heterodyne detection, and a beam expander (6), for facilitating target acquisition, toward a retroreflector (7) located on a target body (80). The returning signal beam (54) is thereby reflected back through the beam expander (6) and Bragg-cell (5) to the resonance mirror (2) of the laser (1), and is now shifted in frequency by 2 Z. The returning signal beam (54) and reference beam (30) are directed into a detector (4) to produce an electrical signal (60). A frequency divider (8) and a phase demodulator (9) extract the phase information (70) of the electrical signal (60) through heterodyne detection, the phase being proportional to the position of the retroreflector (7) and, hence, the target body (80).

23. 发明授权

EP0605229B1 Optical heterodyne detection method and apparatus for applying the method to practical use 失效
标题翻译：对于其实际应用的光学外差检测方法和装置
公开(公告)号：EP0605229B1
公开(公告)日：1999-02-17
申请号：EP93310534.8
申请日：1993-12-24
申请人： SHARP KABUSHIKI KAISHA
发明人： Shimonaka, Atsushi , Morioka, Tatsuya , Taneya, Mototaka , Kawanishi, Hidenori , Takiguchi, Haruhisa
IPC分类号： G01J9/04 , H04B10/10
CPC分类号： H04B10/1121

24. 发明授权

EP0297556B1 Emission spectral width measuring apparatus for light source 失效
标题翻译：用于光源的光谱发射宽度测量装置。
公开(公告)号：EP0297556B1
公开(公告)日：1993-11-10
申请号：EP88110398.0
申请日：1988-06-29
申请人： ANRITSU CORPORATION
发明人： Sonobe, Yoji
IPC分类号： G01J9/04
CPC分类号： G01J9/04

25. 发明公开

EP0567701A1 Inspection method and apparatus 失效
标题翻译： Verfahren undGerätzur Inspektion。
公开(公告)号：EP0567701A1
公开(公告)日：1993-11-03
申请号：EP92305510.7
申请日：1992-06-16
申请人： CANON KABUSHIKI KAISHA
发明人： Tsuji, Toshihiko, c/o Canon Kabushiki Kaisha , Nose, Noriyuki, c/o Canon Kabushiki Kaisha , Yoshii, Minoru, c/o Canon Kabushiki Kaisha , Miyazaki, Kyoichi, c/o Canon Kabushiki Kaisha , Takeuchi, Seiji, c/o Canon Kabushiki Kaisha
IPC分类号： G01N21/88 , G01J9/04
CPC分类号： G03F7/70616 , G01J9/04 , G01J2009/0261 , G01N21/88 , G01N21/8806 , G01N21/94 , G03F7/7065 , G03F7/70916
摘要： An inspection method and apparatus is disclosed, wherein a laser beam from a laser source is separated into two orthogonal, linearly polarized lights which are then modulated at different shift frequencies and are projected on the same spot on a surface to be inspected. Scattered light resulting in response to impingement of one laser beam and resulting from depolarization attributable to a particle or fault on the surface, and zero-th order diffraction light resulting from the other laser beam, are caused to interfere with each other. The resultant interference light is detected through heterodyne detecting method, whereby a beat signal is detected only on the basis of the light depolarized by the particle or fault. This assures precise inspection of a high S/N ratio to a particle or fault on the surface.
摘要翻译：公开了一种检查方法和装置，其中将来自激光源的激光束分成两个正交的线偏振光，然后以不同的移动频率进行调制，并将其投影在待检测的表面上的同一点上。导致响应于一个激光束的冲击并由归因于表面上的颗粒或故障引起的去极化以及由另一个激光束产生的零级衍射光的散射光彼此干涉。通过外差检测方法检测合成的干涉光，由此仅根据由粒子或故障去极化的光检测拍频信号。这确保了对表面上的颗粒或故障的高S / N比的精确检查。

26. 发明授权

EP0314709B1 ZWEI-WELLENLÄNGEN-INTERFEROMETRIE MIT OPTISCHEM HETERODYNVERFAHREN 失效
标题翻译：具有光学异质性过程的双波长干涉
公开(公告)号：EP0314709B1
公开(公告)日：1992-03-11
申请号：EP88902383.4
申请日：1988-03-30
申请人： Leica Heerbrugg AG
发明人： DÄNDLIKER, René
IPC分类号： G01J9/04 , G01B9/02
CPC分类号： G01B9/02007 , G01B9/02003 , G01B9/02027 , G01B9/02067 , G01B2290/70 , G01J9/04 , G01J2009/0207 , G01J2009/0253 , G01J2009/0261
摘要： The device comprises : a laser device (10, 20) for the frequency n1 (11) and the frequency n2 (21), each provided with a polarizing beam splitter (12, 22) for producing crossed polarized partial beams of frequency n1 (13, 14) and n2 (23, 24), respectively, with a modulator (18, 28) for shifting the frequency of each of the partial beams to the frequency f1 or f2, respectively, with a pair of deflecting mirrors (15, 17, 25, 27) and with a polarizing beam splitter (16, 26) for uniting (19, 29) the partial beams n1, n1+f1, n2, n2+f2; two photodetectors (35, 45) before each of which a polarizer (34, 44) is arranged; a Michelson interferometer; a non-polarizing beam splitter (30) for distributing each of the partial beams (19, 29) into a measurement light beam (32) or a reference light beam (33). The reference light beam is transmitted to the corresponding photodetector (35). The measurement light beam (32) is transmitted to the Michelson interferometer and then to the corresponding photodetector (45).The photodetector signals are modulated in function of the amplitude, and the phase difference between the two modulated signals is determined. This phase difference depends only on the position of the test object and the equivalent wavelenght of the difference, n1-n2. For stabilization or correction, the device can be executed in duplicate and one of the executions used as a reference. The corresponding process can be applied to determine positions or distances as the interval between two positions. Uncertainties can be eliminated by shifting the distance or changing the frequency with simultaneous integration of the phase difference over time.

27. 发明公开

EP0428924A2 Frequency detector for discriminating multi-longitudinal mode laser operation 失效
标题翻译：激光Bet。。。。。。。。。。。。。。。。。。。。。
公开(公告)号：EP0428924A2
公开(公告)日：1991-05-29
申请号：EP90121017.9
申请日：1990-11-02
申请人： Hughes Aircraft Company
发明人： Ottusch, John J.
IPC分类号： G01J9/04 , G02F2/00 , H01S3/00 , G01R23/14
CPC分类号： G01J9/04 , G01J2009/004
摘要： A photodetector produces an output signal in response to irradiation by an optical beam from a pulled laser. A delay unit delays the output signal for a period corresponding to one-half of one cycle of a beat frequency generated by interaction of two frequency components in the optical beam corresponding to two predetermined longitudinal modes of operation of the laser. A differential mixer subtractively combines the output of the photodetector with the output of the delay unit, to produce an output signal having the main profile of the laser pulses suppressed, and the beat frequency component, if present, amplified. A resonant circuit and amplifier may be provided to further amplify the beat frequency component. The output of the amplifier is integrated to produce a DC signal having a magnitude which corresponds to the amplitude of the beat frequency component. The DC signal is compared with a threshold value to discriminate between single and multi-mode operation of the laser. An optical shutter may be closed in response to sensed multi-longitudinal mode operation to block the laser beam and protect equipment which would otherwise be damaged thereby.
摘要翻译：光电检测器响应于来自拉动激光器的光束的照射而产生输出信号。延迟单元将对应于对应于激光器的两个预定纵向工作模式的光束中的两个频率分量的相互作用产生的拍频的一个周期的一半周期延迟输出信号。差分混频器将光电检测器的输出与延迟单元的输出相减，以产生抑制激光脉冲的主要轮廓的输出信号，并且如果存在则将拍频分量放大。可以提供谐振电路和放大器以进一步放大拍频分量。放大器的输出被积分以产生具有对应于节拍频率分量的振幅的幅度的DC信号。将DC信号与阈值进行比较，以区分激光器的单模式和多模式操作。可以响应于感测的多纵模式操作来闭合光学快门来阻挡激光束并保护否则将由此损坏的设备。

28. 发明公开

EP0297556A3 Emission spectral width measuring apparatus for light source 失效
标题翻译：用于光源的发射光谱宽度测量装置
公开(公告)号：EP0297556A3
公开(公告)日：1991-03-06
申请号：EP88110398.0
申请日：1988-06-29
申请人： ANRITSU CORPORATION
发明人： Sonobe, Yoji
IPC分类号： G01J9/04
CPC分类号： G01J9/04
摘要： A measurement beam emitted from a laser diode is split into two beams by a beam splitter (12), and one of the two beams is guided to a first port (201) of an acoustic optical element (20). When a high-frequency signal is applied from a diffraction controller (22) to a piezoelectric transducer (205), the split beam input into the acoustic optical element (20) from the first port (201) is diffracted and frequency-shifted and output from a second port (202). If the high-frequency signal is not applied, the input beam rectilinearly propagates without diffracting and is output from a third port (203). This output beam is guided to a fourth port (204) through an optical fiber (24). The beam input from the fourth port (204) rectilinearly propagates and is output from the second port (202). The beam output from the second port (202) is mixed with the other measurement beams split by the beam splitter (12) to be converted to an electrical signal. The electrical signal is analyzed by a spectrum analyzer (28). When the high-frequency signal is applied to the piezoelectric transducer (205), measurement using an optical heterodyne spectroscopy is performed, and when the high-frequency signal is not applied, measurement using an optical homodyne spectroscopy is performed.

29. 发明授权

EP0172568B1 Method of and device for realtime measurement of the state of polarization of a quasi-monochromatic light beam 失效
标题翻译：用于实时测量准单色光束偏振状态的方法和装置
公开(公告)号：EP0172568B1
公开(公告)日：1990-12-05
申请号：EP85110477.8
申请日：1985-08-21
申请人： CSELT Centro Studi e Laboratori Telecomunicazioni S.p.A.
发明人： Calvani, Riccardo , Cisternino, Francesco , Caponi, Renato
IPC分类号： G01J4/00 , G01J9/04
CPC分类号： G01J4/00 , G01J9/04

30. 发明公开

EP0307960A3 Optical heterodyne detector 失效
标题翻译：光学异位检测器
公开(公告)号：EP0307960A3
公开(公告)日：1990-06-20
申请号：EP88115329.0
申请日：1988-09-19
申请人： HAMAMATSU PHOTONICS KABUSHIKI KAISHA
发明人： Aoshima, Shinichiro , Takemori, Tamiki , Tsuchiya, Yutaka
IPC分类号： G01J9/04
CPC分类号： H04B10/60 , G01J9/04 , H04B10/64
摘要： An optical heterodyne detector comprising means for causing two light beams to intefere with each other and producing interference light beams thereof, a streak camera for receiving the interference light beams and analyzing means for analyzing an output of the streak camera, thereby to detect a beat frequency of the two light beams.

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