公开(公告)号：US06829083B2

公开(公告)日：2004-12-07

申请号：US10745969

申请日：2003-12-29

申请人： Takafumi Terahara

发明人： Takafumi Terahara

IPC分类号： H01S300

CPC分类号： H04B10/2941 ,  H01S3/10023 ,  H04B10/2935 ,  H04B2210/258 ,  H04J14/0221

摘要： The present invention relates to a method for gain equalization, for example. First, an optical transmission line including an optical amplifier having a gain changing nonlinearly with wavelength is provided (step (a)). Secondly, gain equalization of the optical transmission line is performed so as to obtain a gain changing substantially linearly with wavelength (step (b)). Finally, gain equalization of the optical transmission line is performed so as to obtain a gain remaining substantially unchanged with wavelength (step (c)). According to this method, gain equalization of the optical transmission line is performed so as to obtain a gain changing substantially linearly with wavelength. Accordingly, variations in equalization error due to changes in system condition can be easily suppressed.

摘要翻译： 本发明涉及一种增益均衡的方法。 首先，提供包括具有波长非线性变化的光放大器的光传输线（步骤（a））。 其次，进行光传输线的增益均衡，以获得基本上与波长线性变化的增益（步骤（b）））。 最后，进行光传输线的增益均衡，以获得与波长保持大致不变的增益（步骤（c）））。 根据该方法，进行光传输线路的增益均衡，以获得基本上以波长线性变化的增益。 因此，可以容易地抑制由于系统状态的变化引起的均衡误差的变化。

公开(公告)号：US06741389B2

公开(公告)日：2004-05-25

申请号：US10093818

申请日：2002-03-11

申请人： Junichi Kumasako ,  Takafumi Terahara

发明人： Junichi Kumasako ,  Takafumi Terahara

IPC分类号： H01S300

CPC分类号： H04B10/2916 ,  H04B2210/003 ,  H04B2210/258

摘要： The present invention aims at providing an optical transmission system for improving transmission characteristics, taking account of the nonlinear optical effect to be caused not only in an optical fiber transmission path wherein the distributed Raman amplification is performed but also in an amplifying medium wherein the discrete Raman amplification is performed, within an optical transmission device. To this end, the optical transmission system of the present invention controls, in each repeating section, the supplying conditions of pumping lights at a distributed Raman amplifier and a discrete Raman amplifier, based on signal light powers at a signal light input point to the optical fiber transmission path and a signal light output point from the optical fiber transmission path, and signal light powers at a signal light input point to a DCF (amplifying medium) and a signal light output point from the DCF within an optical repeater, so that an amount of nonlinear optical effect caused in one repeating section is brought to a required value or less.

摘要翻译： 本发明的目的在于提供一种用于提高传输特性的光传输系统，其考虑到不仅在其中执行分布式拉曼放大的光纤传输路径中引起的非线性光学效应，而且在其中分立拉曼 在光传输装置内进行放大。 为此，本发明的光传输系统在每个重复部分中控制在分布式拉曼放大器和离散拉曼放大器处的泵浦光的供给条件，基于在光信号光输入点处的信号光功率 光纤传输路径和来自光纤传输路径的信号光输出点，并且信号光在光中继器内的DCF（放大介质）的信号光输入点和来自DCF的信号光输出点供电，使得 在一个重复部分中引起的非线性光学效果的数量达到所需值或更小。

公开(公告)号：US06721481B2

公开(公告)日：2004-04-13

申请号：US09984489

申请日：2001-10-30

申请人： Takafumi Terahara ,  Rainer Hainberger ,  Takeshi Hoshida

发明人： Takafumi Terahara ,  Rainer Hainberger ,  Takeshi Hoshida

IPC分类号： G02B600

CPC分类号： H04B10/2916 ,  G02B6/02252 ,  G02B6/02266 ,  G02B6/262 ,  G02B6/29377 ,  H01S3/302 ,  H04B10/25253 ,  H04B2210/003

摘要： An optical fiber transmission line including first, second and third optical fibers connected together so that light travels through the transmission line from the first optical fiber, then through the second optical fiber and then through the third optical fiber. The first, second and third optical fibers have first, second and third characteristic values, respectively. The second characteristic value is larger than the first characteristic value and the third characteristic value. The characteristic value of a respective optical fiber being a nonlinear refractive index of the optical fiber divided by an effective cross section of the optical fiber. Pump light is supplied to the transmission line so that Raman amplification occurs in the transmission line as an optical signal travels through the transmission line.

摘要翻译： 一种光纤传输线，包括连接在一起的第一，第二和第三光纤，使得光从第一光纤传播通过传输线，然后穿过第二光纤，然后通过第三光纤。 第一，第二和第三光纤分别具有第一，第二和第三特性值。 第二特征值大于第一特征值和第三特征值。 作为光纤的非线性折射率的各光纤的特征值除以光纤的有效截面。 泵浦光被提供给传输线，使得当光信号通过传输线路时，在传输线路中发生拉曼放大。

公开(公告)号：US06647211B2

公开(公告)日：2003-11-11

申请号：US10067302

申请日：2002-02-07

申请人： Takafumi Terahara ,  Terumi Chikama

发明人： Takafumi Terahara ,  Terumi Chikama

IPC分类号： H04B1000

CPC分类号： H04J14/021 ,  H04B10/077 ,  H04B10/07955 ,  H04J14/02 ,  H04J14/0206 ,  H04J14/0212 ,  H04J14/0213

摘要： The invention provides a remote control device of an acousto-optic tunable filter, which comprises an acousto-optic tunable filter interpolated in an optical transmission line, capable of controlling an output state of an input light signal by being supplied with a surface acoustic wave control signal through a control port; a surface acoustic wave control signal source to generate the surface acoustic wave control signal, which is provided at a remote place from the acousto-optic tunable filter; and a control unit that receives an information of the surface acoustic wave control signal from the surface acoustic wave control signal source through remote transmission means, and supplies the surface acoustic wave control signal to the control port of the acousto-optic tunable filter. According to this invention, the scale of the device using the acousto-optic tunable filter becomes enlarged, the power consumption is increased; and the man power required for the maintenance of the devices can be reduced, and the remote control of the acousto-optic tunable filter can be achieved.

摘要翻译： 本发明提供了一种声光可调谐滤波器的遥控装置，其包括在光传输线内插的声光可调谐滤波器，能够通过提供表面声波控制来控制输入光信号的输出状态 信号通过控制端口; 表面声波控制信号源，用于产生声表面波控制信号，该声表面波控制信号设置在距离声光可调滤波器的远处; 以及控制单元，其通过远程发送装置从声表面波控制信号源接收声表面波控制信号的信息，并将声表面波控制信号提供给声光可调谐滤波器的控制端口。 根据本发明，使用声光可调谐滤波器的装置的规模变大，功耗增加; 并且可以减少维护设备所需的人力，并且可以实现声光可调谐滤波器的远程控制。

公开(公告)号：US06535309B1

公开(公告)日：2003-03-18

申请号：US09172244

申请日：1998-10-14

申请人： Takafumi Terahara

发明人： Takafumi Terahara

IPC分类号： H04J1402

CPC分类号： G02B6/2932 ,  H04J14/0201 ,  H04J14/0221

摘要： The present invention aims at providing optical multiplexing/demultiplexing apparatus and method, in which an optical power balance of each wavelength light of a wavelength division multiplexed signal light at input and output ports thereof can be maintained. Thus, an optical multiplexing/demultiplexing apparatus of the present invention has a basic constitution consisting of: an OADM circuit for branching a signal light of a specific wavelength from a wavelength-division-multiplexed signal light sent from a main optical fiber, and for inserting a signal light of a specific wavelength into the wavelength-division-multiplexed signal light sent from a main optical fiber; and an add-light power control portion for controlling the optical power of add light added in the OADM circuit based on a drop light branched in the OADM circuit. In the add-light power control portion, the optical power of each of drop light and add light is measured to perform a control operation of controlling the ratio between the optical power of the drop light and the optical power of the add light to be constant. Consequently, the optical power of signal light of each wavelength at input and output ports of the optical multiplexing/demultiplexing apparatus can be maintained at a constant level.

摘要翻译： 本发明的目的在于提供一种光复用/解复用装置和方法，其中可以保持其输入和输出端口处的波分复用信号光的每个波长光的光功率平衡。 因此，本发明的光复用/解复用装置具有以下基本结构：OADM电路，用于从主光纤发送的波分复用信号光分支特定波长的信号光，并插入 将特定波长的信号光转换成从主光纤发送的波分复用信号光; 以及附加光功率控制部分，用于基于在OADM电路中分支的液滴光来控制在OADM电路中添加的添加光的光功率。 在附加光功率控制部分中，测量每个滴光和增加光的光功率，以执行控制操作，以控制滴光的光功率与添加光的光功率之间的比率恒定 。 因此，可以将光复用/解复用装置的输入和输出端口处的每个波长的信号光的光功率保持在恒定水平。

公开(公告)号：US06344914B1

公开(公告)日：2002-02-05

申请号：US08805825

申请日：1997-02-26

申请人： Naomasa Shimojoh ,  Takafumi Terahara ,  Terumi Chikama

发明人： Naomasa Shimojoh ,  Takafumi Terahara ,  Terumi Chikama

IPC分类号： H04B1002

CPC分类号： H04B10/2941 ,  H01S3/10023 ,  H01S3/1312 ,  H01S2301/04 ,  H04B10/2942 ,  H04J14/0221

摘要： A gain equalizer which equalizes gain versus wavelength characteristics of an optical amplifier. The gain versus wavelength characteristics of the optical amplifier include first, second and third gain peaks in a wavelength band with the second gain peak being between the first and third gain peaks. The optical amplifier amplifies an input signal in accordance with the gain versus wavelength characteristics to produce an output signal. The gain equalizer includes first, second and third optical filters having first, second and third transparency characteristics, respectively. The first, second and third transparency characteristics are periodic waveforms having different periods related to the wavelength difference between the first and third gain peaks. The second transparency characteristic is a periodic waveform having a period equal to 1/(2n) of the period of the waveform of the first transparency characteristic. The third transparency characteristic is a periodic waveform having a period equal to ¼ of the period of the waveform of the first transparency characteristic. For example, the first transparency characteristic is a periodic waveform with ¼ period extending between the first and third gain peaks, the second transparency characteristic is a periodic waveform with one period extending between the first and third gain peaks, and the third transparency characteristic is a periodic waveform with two periods extending between the first and third gain peaks.

摘要翻译： 增益均衡器，其均衡光放大器的增益对波长特性。 光放大器的增益对波长特性包括波长带中的第一，第二和第三增益峰值，第二增益峰值在第一和第三增益峰值之间。 光放大器根据增益对波长特性来放大输入信号以产生输出信号。 增益均衡器包括分别具有第一，第二和第三透明特性的第一，第二和第三滤光器。 第一，第二和第三透明度特征是具有与第一和第三增益峰值之间的波长差有关的不同周期的周期性波形。 第二透明特性是周期等于第一透明特性的波形的周期的1 /（2n）的周期波形。 第三透明特性是周期等于第一透明特性的波形周期的1/4的周期波形。 例如，第一透明特性是在第一和第三增益峰之间延伸的1/4周期的周期波形，第二透明特性是周期性波形，其中一个周期在第一和第三增益峰之间延伸，第三透明特性是 具有在第一和第三增益峰之间延伸的两个周期的周期性波形。

公开(公告)号：US06307656B2

公开(公告)日：2001-10-23

申请号：US09778774

申请日：2001-02-08

申请人： Takafumi Terahara

发明人： Takafumi Terahara

IPC分类号： H04J1402

CPC分类号： H04J14/021 ,  H04J14/0206 ,  H04J14/0209 ,  H04J14/0212 ,  H04J14/0213 ,  H04J14/0216 ,  H04J14/0217 ,  H04J14/0221

摘要： An optical device has an optical switching unit and a variable filter, the optical switching unit connects a pair of single direction optical transmission lines to a bi-directional optical transmission line carrying optical signals of different wavelengths in different directions relative to the optical switching unit. The single direction optical transmission lines carry optical signals in single different directions relative to the optical switching unit. The variable filter has first and second opposing terminal pairs such that optical signals of different wavelengths input to one terminal of one terminal pair are filtered with a portion of the different wavelengths being output to one terminal of the opposing terminal pair and the remainder of the different wavelengths being output to the other terminal of the opposing terminal pair. The bi-directional optical transmission line is coupled to one terminal of the variable filter. The optical switching unit may include an optical circulator. The variable filter may be an acousto-optic tunable filter. The optical device have a pair of optical switching units respectively connecting two pairs of single direction optical transmission lines to two opposing terminals of the variable filter through two bi-directional optical transmission lines.

摘要翻译： 光学装置具有光学开关单元和可变滤波器，光开关单元将一对单向光传输线连接到双向光传输线路，该双向光传输线路相对于光开关单元在不同方向上携载不同波长的光信号。 单向光传输线相对于光开关单元在单个不同方向上携带光信号。 可变滤波器具有第一和第二相对端子对，使得输入到一个端子对的一个端子的不同波长的光信号被不同波长的一部分输出到相对端子对的一个端子并且其余的不同的 波长输出到相对端子对的另一个端子。 双向光传输线耦合到可变滤波器的一个端子。 光开关单元可以包括光循环器。 可变滤波器可以是声光可调滤波器。 该光学器件具有一对光开关单元，其通过两个双向光传输线分别将两对单向光传输线路连接到可变滤波器的两个相对端子。

公开(公告)号：US06271945B1

公开(公告)日：2001-08-07

申请号：US09395168

申请日：1999-09-14

申请人： Takafumi Terahara

发明人： Takafumi Terahara

IPC分类号： H04J1402

CPC分类号： H04J14/0221 ,  H04B10/505 ,  H04B10/506 ,  H04B10/564

摘要： An apparatus and method for controlling power levels of individual signal lights of a wavelength division multiplexed (WDM) signal light. The apparatus includes an optical fiber, a coupler and a controller. The WDM signal light travels through the optical fiber. The WDM signal light includes a plurality of individual signal lights which each have a corresponding power level. The coupler decouples a portion of the WDM signal light from the optical fiber. The controller determines the spectrum of the WDM signal light from the decoupled portion and controls the power levels of the plurality of individual signal lights in accordance with the determined spectrum. More specifically, the controller can control the relative power levels of the plurality of individual signal lights with respect to each other. In addition, the controller can control the power levels of the plurality of individual signal lights to perform preemphasis on the WDM signal light. The controller can control the power levels of the plurality of individual signal lights to obtain substantially equal signal to noise ratios of the plurality of individual signal lights as received by a receiver through the optical fiber. The method includes the steps of (a) decoupling a portion of a WDM signal light travelling through an optical fiber (b) determining the spectrum of the WDM signal light from the decoupled portion, and (c) controlling the power levels of individual signal lights of the WDM signal light in accordance with the determined spectrum.

摘要翻译： 一种用于控制波分复用（WDM）信号光的各信号光的功率电平的装置和方法。 该装置包括光纤，耦合器和控制器。 WDM信号光穿过光纤。 WDM信号灯包括多个单独的信号灯，每个信号灯具有相应的功率电平。 耦合器将WDM信号光的一部分与光纤分离。 控制器确定来自解耦部分的WDM信号光的光谱，并根据所确定的光谱来控制多个单独信号光的功率电平。 更具体地，控制器可以相对于彼此控制多个个体信号光的相对功率电平。 此外，控制器可以控制多个单独的信号光的功率电平来对WDM信号光进行预加重。 控制器可以控制多个单独的信号光的功率电平，以获得由接收机通过光纤接收的多个单独的信号光的信噪比。 该方法包括以下步骤：（a）将通过光纤传播的WDM信号光的一部分去耦（b），以确定来自解耦部分的WDM信号光的光谱，以及（c）控制各信号光的功率电平 的WDM信号光。

公开(公告)号：US06222655B1

公开(公告)日：2001-04-24

申请号：US09007655

申请日：1998-01-15

申请人： Takafumi Terahara

发明人： Takafumi Terahara

IPC分类号： H04J1402

CPC分类号： H04B10/2941 ,  H04J14/0221

摘要： A wavelength division multiplex optical amplification transmission system has a broad signal wavelength band and can be easily constructed. A transmission line provided between a lightwave transmitting terminal station and a lightwave receiving terminal station is constructed of optical amplifiers, optical filters and a transmission line. Structuring the transmission line involves the use of an optical amplifier utilizing high-concentration Al added EDFA, thereby proving a module excluding the optical filters with a gain wavelength characteristic in which a gain peak exists within a target wavelength range that should be a signal wavelength band, and there is an ill-balanced symmetry with respect to the gain peak in the target wavelength range. Used is the optical filter given a loss wavelength characteristic in which a loss maximum wavelength with a maximum loss exists in the target wavelength range, a gain simply decreases as a distance from the loss maximum wavelength increases within the target wavelength range, and a characteristic obtained by adding the loss wavelength characteristics is relatively coincident in values with the gain wavelength characteristic.

摘要翻译： 波分复用光放大传输系统具有宽的信号波长带，并且可以容易地构造。 设置在光波发射终端站和光波接收终端站之间的传输线由光放大器，光滤波器和传输线构成。 构造传输线包括使用利用高浓度Al添加的EDFA的光放大器，从而证明除了具有增益波长特性的滤光器之外的模块，其中增益峰值存在于应当是信号波长带的目标波长范围内 并且相对于目标波长范围内的增益峰值存在不平衡的对称性。 使用的是具有损耗波长特性的滤光器，其中在目标波长范围内存在具有最大损耗的损耗最大波长，随着距离损耗最大波长的距离在目标波长范围内增加，增益简单地减小，并且获得的特性 通过添加损耗波长特性在具有增益波长特性的值中相对一致。

公开(公告)号：US6061172A

公开(公告)日：2000-05-09

申请号：US162144

申请日：1998-09-29

申请人： Takao Naito ,  Naomasa Shimojoh ,  Takafumi Terahara

发明人： Takao Naito ,  Naomasa Shimojoh ,  Takafumi Terahara

IPC分类号： G02B5/18 ,  G02B6/02 ,  H01S3/06 ,  H01S3/067 ,  H01S3/07 ,  H01S3/094 ,  H01S3/10 ,  H01S3/16 ,  H01S3/00

CPC分类号： H01S3/094003 ,  H01S3/0675 ,  H01S3/1608

摘要： The present invention aims at providing an active optical fiber and an optical fiber amplifier, in which a conversion efficiency of pumping light to be input into the active optical fiber is increased to thereby improve optical amplification characteristic. To this end, the active optical fiber of the present invention is formed with fiber gratings arranged over a predetermined region along the longitudinal direction within the optical fiber doped with a rare earth element, and transmitting signal light and reflecting pumping light. Further, the optical fiber amplifier of the present invention is constituted to comprise a pumping light source for generating pumping light, and a multiplexer for multiplexing signal light and the pumping light to thereby output them into one end of the active optical fiber. Thus, the pumping light is reflected by the fiber gratings so as to go and return within the active optical fiber, thereby improving the conversion efficiency of the pumping light.

摘要翻译： 本发明的目的在于提供一种有源光纤和光纤放大器，其中增加输入有源光纤的泵浦光的转换效率，从而提高光放大特性。 为此，本发明的有源光纤由掺杂有稀土元素的光纤内沿着长度方向的预定区域配置的光纤光栅形成，并且传输信号光并反射泵浦光。 此外，本发明的光纤放大器构成为包括用于产生泵浦光的泵浦光源和用于复用信号光的多路复用器和泵浦光，从而将其输出到有源光纤的一端。 因此，泵浦光被光纤光栅反射，从而在有源光纤内返回，从而提高了泵浦光的转换效率。