公开(公告)号：US07697122B2

公开(公告)日：2010-04-13

申请号：US12065658

申请日：2006-09-04

Applicant: Tomoyu Yamashita ,  Eiji Kato

Inventor： Tomoyu Yamashita ,  Eiji Kato

IPC: G01N21/00

CPC classification number: G01N21/3581 ,  G01M11/335

Abstract: A frequency resolution for measuring transmission characteristics of a device under test is increased. With a measuring device including a first terahertz light generator that generates incident light, a second terahertz light generator that generates reference light having an optical frequency f1−f2−fIF different from an optical frequency f1−f2 of the incident light by a constant difference frequency fIF, a terahertz light detector which outputs an light detection signal having the difference frequency fIF based on response light obtained by making the incident light incident to an optical fiber and the reference light, and a network analyzer that receives the light detection signal, thereby measuring characteristics of the optical fiber, a spectrum of the incident light (terahertz light) incident to the optical fiber includes the carrier frequency (f1−f2), but does not include sideband frequencies (f1−f2±fIF). It is thus possible to reduce the effective spectrum width of the incident light. As a result, the frequency resolution increases in the measurement of the transmission characteristics of the optical fiber.

Abstract translation: 用于测量被测设备的传输特性的频率分辨率增加。 利用包括产生入射光的第一太赫兹光发生器的测量装置，产生具有与入射光的光频率f1-f2不同的光频率f1-f2-fIF的参考光的第二太赫兹光发生器，该参考光具有恒定的差频 fIF是基于通过使入射到光纤的入射光和参考光获得的响应光输出具有差频fIF的光检测信号的太赫兹光检测器，以及接收光检测信号的网络分析器，由此测量 光纤的特性，入射到光纤的入射光（太赫兹光）的光谱包括载波频率（f1-f2），但不包括边带频率（f1-f2±fIF）。 因此可以降低入射光的有效光谱宽度。 结果，在光纤的传输特性的测量中频率分辨率增加。

公开(公告)号：US08676061B2

公开(公告)日：2014-03-18

申请号：US12940131

申请日：2010-11-05

Applicant: Tomoyu Yamashita ,  Akiyoshi Irisawa

Inventor： Tomoyu Yamashita ,  Akiyoshi Irisawa

IPC: H04B10/04 ,  H04B10/12

CPC classification number: H03L7/22

Abstract: A frequency converter includes a first direct digital synthesizer that receives a signal having a predetermined frequency f_master as a clock signal and further an internal frequency setting signal, and outputs an internal signal having a frequency based on the internal frequency setting signal, and a second direct digital synthesizer that receives the internal signal as a clock signal, and further an output frequency setting signal, and outputs an output signal having a frequency f_slave (=f_master−Δ) based on the output frequency setting signal. A difference between the predetermined frequency f_master and the frequency of the internal signal is larger than a difference between the predetermined frequency f_master and the frequency f_slave of the output signal.

Abstract translation: 频率转换器包括：第一直接数字合成器，其接收具有预定频率f_master的信号作为时钟信号，并且还具有内部频率设置信号，并输出具有基于内部频率设置信号的频率的内部信号;以及第二直接 数字合成器，其接收内部信号作为时钟信号，以及输出频率设定信号，并根据输出频率设定信号输出具有频率f_slave（= f_master-Delta）的输出信号。 预定频率f_master与内部信号的频率之间的差异大于预定频率f_master与输出信号的频率f_slave之差。

公开(公告)号：US08493057B2

公开(公告)日：2013-07-23

申请号：US12731483

申请日：2010-03-25

Applicant: Shigeki Nishina ,  Motoki Imamura ,  Akiyoshi Irisawa ,  Tomoyu Yamashita ,  Eiji Kato ,  Kodo Kawase

Inventor： Shigeki Nishina ,  Motoki Imamura ,  Akiyoshi Irisawa ,  Tomoyu Yamashita ,  Eiji Kato ,  Kodo Kawase

IPC: G01S3/02

CPC classification number: G01J5/0285 ,  G01N21/3563 ,  G01N21/3581 ,  G01N21/8806

Abstract: A detector detects an electromagnetic wave having a frequency of 0.01 THz≦f≦100 THz and transmitted through a device under test (DUT). A changer changes a relative position of an intersection of an optical path of the electromagnetic wave and the DUT, with respect to the DUT. A deriver derives a characteristic value of the electromagnetic wave based on a detection result of the detector, while the characteristic value is associated with an assumed relative position, which is the relative position if the electromagnetic wave is not refracted by the DUT. A corrector changes the assumed relative position to an actual relative position, which is the relative position if the refraction of the electromagnetic wave by the DUT is considered. A corrected deriver derives the characteristic value associated with a predetermined relative position based on an output from the corrector.

Abstract translation: 检测器检测频率为0.01THz @ f @ 100THz的电磁波，并通过被测器件（DUT）传输。 变换器相对于DUT来改变电磁波和DUT的光路的交点的相对位置。 导出器基于检测器的检测结果导出电磁波的特征值，而特征值与假设的相对位置相关联，假设的相对位置是电磁波未被DUT折射的相对位置。 校正器将假设的相对位置改变为实际的相对位置，如果考虑到DUT的电磁波的折射，则相对位置是相对位置。 校正后的发生器基于校正器的输出导出与预定相对位置相关联的特征值。

公开(公告)号：US08306078B2

公开(公告)日：2012-11-06

申请号：US13299568

申请日：2011-11-18

Applicant: Tomoyu Yamashita ,  Akiyoshi Irisawa

Inventor： Tomoyu Yamashita ,  Akiyoshi Irisawa

IPC: H01S3/13

CPC classification number: H01S3/10046 ,  H01S3/1394

Abstract: A repetition frequency control device includes a slave photoelectric conversion unit which converts a slave laser light pulse into a slave electrical signal, a master photoelectric conversion unit which converts a master laser light pulse into a master electrical signal, a frequency change unit which changes the repetition frequency of the master electric signal by a predetermined value, a phase comparator which detects a phase difference between the slave electric signal and the output from the frequency change unit, and a loop filter which removes a high frequency component of an output from the phase comparator, where the repetition frequency of the master laser does not undergo control based on one or both of the master electric signal and the slave electric signal.

Abstract translation: 重复频率控制装置包括将从属激光光脉冲转换为从属电信号的从光电转换单元，将主激光光脉冲转换成主电信号的主光电转换单元，改变重复的频率改变单元 主电信号的频率达预定值，检测从电信号与频率改变单元的输出之间的相位差的相位比较器，以及从相位比较器去除输出的高频分量的环路滤波器 ，其中主激光器的重复频率不基于主电信号和从电信号中的一个或两个进行控制。

公开(公告)号：US20050052638A1

公开(公告)日：2005-03-10

申请号：US10491787

申请日：2002-10-09

Applicant: Takeshi Ozeki ,  Tomoyu Yamashita ,  Motoki Imamura

Inventor： Takeshi Ozeki ,  Tomoyu Yamashita ,  Motoki Imamura

IPC: G01M11/02 ,  G01M11/00 ,  G01J4/00

CPC classification number: G01M11/333 ,  G01M11/336

Abstract: A polarization mode dispersion measuring device reduced in time required to measure polarization mode dispersion τPMD. A polarization controller (12) allows a first (second) incident light to apply a synthetic incident light to an object to be measured (30) in line with a p-polarization axis (s-polarization axis) in a polarization separator (16). Accordingly, the phase shift equivalent value (optical angle frequency differentiation) and amplitude equivalent value (square value) of a first incident light component (second incident light component) in an output from the polarization separator (16) measured by a first measuring unit (20a) (second measuring unit (20b)) are respectively the phase shift equivalent value and amplitude equivalent value of a first column T11, T21 (second column T12, T22) when the transfer function matrix of the object to be measured (30) is a 2×2 matrix to thereby allow a control unit (2) to determine the polarization mode dispersion r PMD of the object to be measured (30). Since there is no need of switching the orientation setting of light output from the polarization controller (12) with the setting left fixed, time required to measure polarization mode dispersion τPMD can be shortened.

Abstract translation: 偏振模色散测量装置减少测量偏振模色散τPMD所需的时间。 偏振控制器（12）允许第一（第二）入射光根据偏振分离器（16）中的p偏振轴（s偏振轴）将合成入射光施加到待测量对象（30） 。 因此，由第一测量单元测量的偏振分离器（16）的输出中的第一入射光分量（第二入射光分量）的相移等效值（光学角度频率微分）和振幅等效值（平方值） 20a）（第二测量单元（20b））分别是当被测量对象（30）的传递函数矩阵为（30）时的第一列T11，T21（第二列T12，T22）的相移等效值和振幅当量值 2×2矩阵，从而允许控制单元（2）确定被测量物体的偏振模色散r PMD（30）。 由于不需要将固定的偏振控制器（12）的光的输出的取向设置切换，所以可以缩短测量偏振模色散τPMD所需的时间。

公开(公告)号：US08718108B2

公开(公告)日：2014-05-06

申请号：US13310130

申请日：2011-12-02

Applicant: Tomoyu Yamashita ,  Akiyoshi Irisawa

Inventor： Tomoyu Yamashita ,  Akiyoshi Irisawa

IPC: H01S3/139 ,  H01S3/10

CPC classification number: H01S3/10046 ,  H01S3/1394

Abstract: According to the repetition frequency control device, a master laser outputs a master laser light pulse the repetition frequency of which is controlled to a predetermined value. A slave laser outputs a slave laser light pulse. A reference comparator compares a voltage of a reference electric signal the repetition frequency of which is the predetermined value and a predetermined voltage with each other, thereby outputting a result thereof. A measurement comparator compares a voltage based on a light intensity of the slave laser light pulse and the predetermined voltage with each other, thereby outputting a result thereof. A phase difference detector detects a phase difference between the output from the reference comparator and the output from the measurement comparator. A loop filter removes a high-frequency component of an output from the phase difference detector.

Abstract translation: 根据重复频率控制装置，主激光器将重复频率被控制为预定值的主激光光脉冲输出。 从激光器输出从激光脉冲。 参考比较器将重复频率为预定值的参考电信号的电压与预定电压进行比较，从而输出其结果。 测量比较器将基于从激光光脉冲的光强度和预定电压的电压彼此进行比较，从而输出其结果。 相位差检测器检测来自参考比较器的输出与测量比较器的输出之间的相位差。 环路滤波器去除相位差检测器的输出的高频分量。

公开(公告)号：US06426792B1

公开(公告)日：2002-07-30

申请号：US09901149

申请日：2001-07-10

Applicant: Tomoyu Yamashita

Inventor： Tomoyu Yamashita

IPC: G01N2100

CPC classification number: G01M11/335 ,  G01M11/333 ,  G01M11/338

Abstract: The object of the present invention is to provide an apparatus that can perform measurement of chromatic dispersion, even if the wavelength of variable-wavelength light source and that of fixed-wavelength light source for reference are identical with each other. The variable-wavelength light generated by a variable-wavelength light source 12 is subjected to intensity modulation to a frequency f by a first optical modulator 15a and transmitted from one end 30a to the other end 30b of an optical fiber 30. The fixed-wavelength light generated by a fixed-wavelength light source 14 is subjected to intensity modulation to a frequency f by a second optical modulator 15b and transmitted from the other end 30b to the one end 30a of optical fiber 30. Therefore, it is possible to separately obtain the variable-wavelength light and fixed-wavelength light transmitted through the optical fiber 30 using a second directional coupler 28 and a first directional coupler 26, respectively, regardless of wavelengths thereof. Accordingly, it is also possible to perform the comparison of phase and measurement of chromatic dispersion, even if the wavelengths of variable-wavelength light source and fixed-wavelength light source for reference are identical with each other.

Abstract translation: 本发明的目的是提供一种可以执行色散测量的装置，即使可变波长光源的波长和用于参考的固定波长光源的波长彼此相同。 由可变波长光源12产生的可变波长光由第一光调制器15a进行频率f的强度调制，并从光纤30的一端30a传输到另一端30b。固定波长 由固定波长光源14产生的光通过第二光调制器15b进行强度调制到频率f，并从另一端30b传输到光纤30的一端30a。因此，可以分别获得 分别使用第二定向耦合器28和第一定向耦合器26透射通过光纤30的可变波长光和固定波长光，而不管其波长如何。 因此，即使用于参考的可变波长光源和固定波长光源的波长彼此相同，也可以进行色散的相位和测量的比较。

公开(公告)号：US08279438B2

公开(公告)日：2012-10-02

申请号：US12480042

申请日：2009-06-08

Applicant: Tomoyu Yamashita ,  Motoki Imamura

Inventor： Tomoyu Yamashita ,  Motoki Imamura

IPC: G01J3/40

CPC classification number: G01N21/3581 ,  G01J3/42 ,  G01J11/00

Abstract: An object is to enable a change in a frequency for which an electric signal based on an optical signal is measured by a spectrum analyzer. An optical measurement device includes a first photoconductive switch that receives predetermined pulse light from a first laser light source, and outputs terahertz light having the same repetition frequency as the repetition frequency of the predetermined pulse light. The optical measurement device also includes a second photoconductive switch that receives the terahertz light and a sampling light pulse, and outputs a signal corresponding to a power of the terahertz light at a time point when the sampling light pulse is received. The optical measurement device further includes an RF spectrum analyzer that measures a magnitude of the signal corresponding to a measured frequency that changes over time, an optical coupler that outputs a simultaneous light pulse when the predetermined pulse light and the sampling light pulse are simultaneously input, a photo detector that converts the simultaneous light pulse into an electric signal as a trigger signal, and an optical delay circuit that delays the trigger signal.

Abstract translation: 本发明的目的是能够通过频谱分析仪来测量基于光信号的电信号的频率的变化。 光学测量装置包括第一光电开关，其接收来自第一激光光源的预定脉冲光，并输出具有与预定脉冲光的重复频率相同的重复频率的太赫兹光。 光学测量装置还包括接收太赫兹光和采样光脉冲的第二光电开关，并且在接收采样光脉冲的时间点输出对应于太赫兹光的功率的信号。 光学测量装置还包括RF频谱分析仪，其测量对应于随时间变化的测量频率的信号的幅度;当预定脉冲光和采样光脉冲被同时输入时输出同时的光脉冲的光耦合器; 将同步光脉冲转换成电信号作为触发信号的光检测器，以及延迟触发信号的光延迟电路。

公开(公告)号：US20120163404A1

公开(公告)日：2012-06-28

申请号：US13310130

申请日：2011-12-02

Applicant: Tomoyu YAMASHITA ,  Akiyoshi IRISAWA

Inventor： Tomoyu YAMASHITA ,  Akiyoshi IRISAWA

IPC: H01S3/13

CPC classification number: H01S3/10046 ,  H01S3/1394

Abstract: According to the repetition frequency control device, a master laser outputs a master laser light pulse the repetition frequency of which is controlled to a predetermined value. A slave laser outputs a slave laser light pulse. A reference comparator compares a voltage of a reference electric signal the repetition frequency of which is the predetermined value and a predetermined voltage with each other, thereby outputting a result thereof. A measurement comparator compares a voltage based on a light intensity of the slave laser light pulse and the predetermined voltage with each other, thereby outputting a result thereof. A phase difference detector detects a phase difference between the output from the reference comparator and the output from the measurement comparator. A loop filter removes a high-frequency component of an output from the phase difference detector.

Abstract translation: 根据重复频率控制装置，主激光器将重复频率被控制为预定值的主激光光脉冲输出。 从激光器输出从激光脉冲。 参考比较器将重复频率为预定值的参考电信号的电压与预定电压进行比较，从而输出其结果。 测量比较器将基于从激光光脉冲的光强度和预定电压的电压彼此进行比较，从而输出其结果。 相位差检测器检测来自参考比较器的输出与测量比较器的输出之间的相位差。 环路滤波器去除相位差检测器的输出的高频分量。

公开(公告)号：US20120155500A1

公开(公告)日：2012-06-21

申请号：US13299568

申请日：2011-11-18

Applicant: Tomoyu YAMASHITA ,  Akiyoshi IRISAWA

Inventor： Tomoyu YAMASHITA ,  Akiyoshi IRISAWA

IPC: H01S3/13

CPC classification number: H01S3/10046 ,  H01S3/1394

Abstract: A repetition frequency control device includes a slave photoelectric conversion unit which converts a slave laser light pulse into a slave electrical signal, a master photoelectric conversion unit which converts a master laser light pulse into a master electrical signal, a frequency change unit which changes the repetition frequency of the master electric signal by a predetermined value, a phase comparator which detects a phase difference between the slave electric signal and the output from the frequency change unit, and a loop filter which removes a high frequency component of an output from the phase comparator, where the repetition frequency of the master laser does not undergo control based on one or both of the master electric signal and the slave electric signal.

Abstract translation: 重复频率控制装置包括将从属激光光脉冲转换为从属电信号的从光电转换单元，将主激光光脉冲转换成主电信号的主光电转换单元，改变重复的频率改变单元 主电信号的频率达预定值，检测从电信号与频率改变单元的输出之间的相位差的相位比较器，以及从相位比较器去除输出的高频分量的环路滤波器 ，其中主激光器的重复频率不基于主电信号和从电信号中的一个或两个进行控制。