公开(公告)号：US5686986A

公开(公告)日：1997-11-11

申请号：US721575

申请日：1996-09-25

申请人： Zhixien Li ,  Yasushi Sato ,  Shoji Adachi ,  Toshio Kurashima ,  Kaoru Shimizu

发明人： Zhixien Li ,  Yasushi Sato ,  Shoji Adachi ,  Toshio Kurashima ,  Kaoru Shimizu

IPC分类号： G01M11/00 ,  G01M11/02 ,  G02B6/00 ,  G01N21/88

CPC分类号： G01M11/3109 ,  G01M11/3172 ,  G01M11/319 ,  G01M11/33

摘要： Coherent light emitted from a coherent light source 1 is sent as a probe beam through a connector 31 into an optical fiber being measured. A portion of this beam is sent to an optical frequency converter 100 to form an optical pulse train having a frequency which is frequency-swept in steps of a designated frequency at a designated periodicity, and an optical pulse having a designated frequency is extracted from the optical pulse train by an electro-optic switch 18 and sent to the optical fiber being measured. Then, a signal beam exiting the optical fiber being measured is heterodyne-received by means of a local beam passing through either a connecting optical fiber 6 side or a frequency shifter 7 side according to the selection of optical switches 4 and 5. Consequently, it is possible to measure the characteristics of the optical fiber by means of a BOTDR, BOTDA or a COTDR.

摘要翻译： 从相干光源1发射的相干光作为探测光束通过连接器31发送到被测量的光纤中。 该光束的一部分被发送到光频变换器100以形成具有以指定周期以指定频率逐步扫频的频率的光脉冲序列，并且从该频率转换器提取具有指定频率的光脉冲 通过电光开关18将光脉冲串发送到被测量的光纤。 然后，根据光开关4和5的选择，通过本地光束通过连接光纤6侧或移频器7侧，离开被测光纤的信号光束被外差接收。因此， 可以通过BOTDR，BOTDA或COTDR测量光纤的特性。

公开(公告)号：US5880824A

公开(公告)日：1999-03-09

申请号：US924325

申请日：1997-09-05

申请人： Haruyoshi Uchiyama ,  Zhixien Li ,  Yasushi Satoh ,  Toshio Kurashima

发明人： Haruyoshi Uchiyama ,  Zhixien Li ,  Yasushi Satoh ,  Toshio Kurashima

IPC分类号： G01M11/00 ,  G01D5/353 ,  G01L1/24 ,  G01M11/02 ,  G01N21/00

CPC分类号： G01L1/242 ,  G01D5/344 ,  G01D5/35358

摘要： An object of the present invention is to provide an optical fiber strain measuring apparatus which can perform precise measurement without causing any fluctuation in signal level. To achieve the above object the present invention comprises: a polarization plane rotation device 105 which rotates a plane of polarization of an optical pulse; a photo-directional coupler 106 which projects an optical pulse projected from the polarization plane rotation device 105 into an optical fiber 107 to be measured, and projects out backscattering light produced in the optical fiber 107 to be measured; a polarization plane rotation device 160 which rotates a plane of polarization of a reference light; a light mixing device 109 for mixing the backscattering light projected out from the photo-directional coupler 106 and the reference light projected from the polarization plane rotation device 160; and a signal processing section 111 which detects the mixed light projected from the light mixing device 109, converts the detected light into an electrical signal and subjects the electrical signal to a predetermined operational processing to obtain a measurement waveform.

摘要翻译： 本发明的目的是提供一种可以进行精确测量而不引起信号电平波动的光纤应变测量装置。 为了实现上述目的，本发明包括：使光脉冲的偏振平面旋转的偏振面旋转装置105; 将从偏振面旋转装置105投射的光脉冲投射到被测光纤107的光定向耦合器106，投射出待测光纤107中产生的后向散射光; 旋转参考光的偏振平面的偏振面旋转装置160; 用于混合从光定向耦合器106射出的后向散射光和从偏振面旋转装置160投影的参考光的光混合装置109; 以及信号处理部111，其检测从光混合装置109射出的混合光，将检测出的光转换为电信号，并对电信号进行预定的运算处理，得到测定波形。

公开(公告)号：US5781322A

公开(公告)日：1998-07-14

申请号：US696074

申请日：1996-08-13

申请人： Haruyoshi Uchiyama ,  Zhixien Li ,  Kazuo Aida

发明人： Haruyoshi Uchiyama ,  Zhixien Li ,  Kazuo Aida

IPC分类号： G01M11/00 ,  G01J11/00 ,  H04B10/00

CPC分类号： G01J11/00

摘要： An optical pulse signal produced by modulating a continuous laser light by means of a first pulse having a period sufficiently shorter than the atomic lifetime in the upper energy state of a rare earth doped fiber is input to an optical amplifier to be measured, while an output signal from the optical amplifier is modulated by a second pulse synchronized with the first pulse and having a phase difference relative to the first pulse which can be optionally set so that rapid phase adjustment relative to the first pulse is possible based on the phase at the time of minimum optical power. The noise figure of the optical amplifier is then measured based on, the maximum photoelectric power (P.sub.AMP +P.sub.ASE) and the minimum photoelectric power P.sub.ASE of the resultant optical signal.

摘要翻译： 通过在稀土掺杂光纤的上能量状态下通过具有比原子寿命充分短的时间的第一脉冲调制连续激光而产生的光脉冲信号被输入到待测量的光放大器，而输出 来自光放大器的信号由与第一脉冲同步的第二脉冲调制，并具有相对于第一脉冲的相位差，该第一脉冲可以可选地被设置为使得可以基于当时的相位相对于第一脉冲进行快速相位调整 的最小光功率。 然后，基于最终的光信号的最大光电功率（PAMP + PASE）和最小光电功率PASE来测量光放大器的噪声系数。