公开(公告)号：US5134276A

公开(公告)日：1992-07-28

申请号：US594178

申请日：1990-10-09

Applicant: Philip C. D. Hobbs

Inventor： Philip C. D. Hobbs

IPC: G01J1/42 ,  G01J1/16 ,  G01J1/44 ,  G01N21/31 ,  G01S7/48 ,  G01S7/491 ,  H01S3/00 ,  H01S3/13

CPC classification number: G01J1/16 ,  G01S7/493 ,  H01S3/1303

Abstract: A noise suppression system is described for use with a laser measurement system in which a beam sampler divides the laser beam into a signal beam and a sample beam. The signal beam is passed through an optical system before being received at the detector while the sample beam is received directly at the detector. The beam sampler is selected such that the received sample beam has a slightly greater steady-state intensity than the received signal beam. The detector circuitry includes two linear wideband photodetectors which produce respective signal and sample currents of opposite polarity. The sample photocurrent is subdivided into two component currents, one of which has substantially the same direct current (DC) value as the signal photocurrent. This component is combined with the signal photocurrent to cancel undesirable noise components in the original laser beam. In a second embodiment of the invention, the dividing circuitry is controlled in a feedback loop to keep the DC portion of the output current at zero.

公开(公告)号：US4856899A

公开(公告)日：1989-08-15

申请号：US943670

申请日：1986-12-18

Applicant: Hideto Iwaoka ,  Akira Ohte ,  Koji Akiyama

Inventor： Hideto Iwaoka ,  Akira Ohte ,  Koji Akiyama

IPC: G01J3/28 ,  G01J9/04 ,  G02F2/00 ,  H01S3/13 ,  H01S5/0687 ,  H04B10/50 ,  H04B10/572

CPC classification number: H01S5/0687 ,  G01J9/04 ,  G02F2/002 ,  H04B10/50 ,  H04B10/506 ,  H04B10/572 ,  G01J3/28 ,  H01S3/1303

Abstract: An optical frequency analyzer for measuring an optical frequency spectrum with high accuracy, high resolving power and high stability by heterodyne detecting the incident light with the aid of a local oscillator, wherein the local oscillator comprises an optical frequency synthesizer/sweeper or a marker signal attached tunable laser. The optical frequency analyzer can be modified to measure the incident light itself as the object of measurement or light emerging from the object of measurement can be the incident light.

Abstract translation: 一种光频率分析仪，用于借助本地振荡器通过外差检测入射光来测量具有高精度，高分辨能力和高稳定性的光频谱，其中本地振荡器包括光频合成器/扫描器或连接的标记信号 可调谐激光 可以修改光频率分析仪来测量入射光本身，因为测量对象或从测量对象出射的光可以是入射光。

公开(公告)号：US4833681A

公开(公告)日：1989-05-23

申请号：US937359

申请日：1986-12-03

Applicant: Koji Akiyama ,  Akira Ohte ,  Hideto Iwaoka

Inventor： Koji Akiyama ,  Akira Ohte ,  Hideto Iwaoka

IPC: G01J3/28 ,  G01J9/04 ,  G02F1/11 ,  G02F2/00 ,  H01S3/13 ,  H01S5/0687 ,  H04B10/50 ,  H04B10/572

CPC classification number: G02F1/11 ,  G01J9/04 ,  G02F2/002 ,  H01S5/0687 ,  H04B10/50 ,  H04B10/506 ,  H04B10/572 ,  G01J3/28 ,  H01S3/1303

Abstract: Light relative to non-modulated output light emitted from a semiconductor laser is applied to an absorption cell. Frequency modulating signals are converted into amplitude modulation signals of the output light through a modulating means by utilizing absorptive properties of the absorption cell. Transmissive light outputs of the absorption cell are synchronously rectified by a lock in amplifier, and an electric current supplied to the semiconductor laser is controlled so that the output signals of the lock in amplifier are arranged to be a predetermined value. The wavelength of the output light is locked to the absorption line of the standard substance in the absorption cell. Advantageously, the invention stabilizes the instantaneous value of the oscillation frequency.

Abstract translation: 将相对于从半导体激光器发射的未调制输出光的光施加到吸收单元。 频率调制信号通过利用吸收单元的吸收特性通过调制装置转换成输出光的幅度调制信号。 吸收单元的透射光输出通过放大器的锁定同步整流，并且控制提供给半导体激光器的电流，使得放大器中的锁定的输出信号被布置为预定值。 输出光的波长被锁定在吸收单元中的标准物质的吸收线上。 有利地，本发明稳定了振荡频率的瞬时值。

公开(公告)号：US4762988A

公开(公告)日：1988-08-09

申请号：US53893

申请日：1987-05-26

Applicant: Otto A. Strobel

Inventor： Otto A. Strobel

IPC: G02F1/01 ,  G02F1/03 ,  G02F1/21 ,  H01S3/13 ,  G01J1/32 ,  G01B9/02

CPC classification number: H01S3/1303 ,  G02F1/21 ,  G02F1/0123 ,  G02F2001/213 ,  G02F2203/21

Abstract: A circuit arrangement including a controllable optical resonator having a filter characteristic with a transmission peak arranged to pass laser radiation at a wavelength in the region of the transmission peak, wherein the resonator is positioned to receive the laser radiation at an angle such that two modes of the radiation, having respectively different polarization states, and wavelengths, are capable of propagating in the resonator. The resonator has control electrodes connected for receiving a voltage which determines the wavelength of the transmission peak of the filter characteristic and a source connected for applying to the electrodes a square-wave modulating voltage which varies between a first value which causes the transmission peak of the resonator to be substantially at the wavelength of one of the modes and a second value which causes the transmission peak of the resonator to be substantially at the wavelength of the other one of the modes. A device is optically coupled to the resonator for deriving two electrical signals each corresponding to radiation passing through the resonator in a respective one of the two modes. A device is connected for determining the phase difference between the two electrical signals and a device is connected for acting on the resonator in a manner to reduce the phase difference to zero on the basis of at least one of the electrical signals.

Abstract translation: 一种电路装置，包括具有滤波器特性的可控光学谐振器，其具有传输峰值，传输峰值布置成使传输峰值区域中的波长传递激光辐射，其中谐振器被定位成以一定角度接收激光辐射， 分别具有不同的偏振状态和波长的辐射能够在谐振器中传播。 谐振器具有连接的控制电极，用于接收确定滤波器特性的透射峰值的波长的电压和连接到电极的源极，该方波调制电压在引起第 谐振器基本上处于一种模式的波长，第二值使谐振器的透射峰基本上处于另一种模式的波长。 一个装置光耦合到谐振器，用于导出两个电信号，每个电信号对应于在两种模式中的相应一个模式中通过谐振器的辐射。 连接一个装置，用于确定两个电信号之间的相位差，并且一个装置被连接起来以以基于至少一个电信号将相位差减小到零的方式作用在谐振器上。