公开(公告)号：US06212003B1

公开(公告)日：2001-04-03

申请号：US09403051

申请日：1999-10-12

申请人： Hiroshi Komazawa ,  Yukio Tsuda

发明人： Hiroshi Komazawa ,  Yukio Tsuda

IPC分类号： H01S300

CPC分类号： G01M11/333 ,  G01M11/335

摘要： In an optical amplifier evaluating system of this invention, a pulse method using optical modulators and a probe method are combined to obtain a gain G and noise figure NF of an optical fiber amplifier. A first optical modulator turns on and off signal light output from a first light source. An optical multiplexer multiplexes the optical signal turned on and off by the first optical modulator and probe light output from a second light source. This optical signal multiplexed by the optical multiplexer is selectively fed into an optical fiber amplifier. A controller properly switches optical path switches to allow an optical spectrum analyzer to measure (1) the light intensity of an input signal of the probe light to the optical fiber amplifier, (2) the light intensity in a region where signal light extracted from the output signal light from the optical fiber amplifier by a second optical modulator is in an OFF period and the probe light is output, and (3) the light intensity in a region where the signal light extracted by the second optical modulator is in the OFF period and no probe light is output. On the basis of measured light intensities (1), (2), and (3), the controller calculates the gain G and noise figure NF of the optical fiber amplifier. In this manner, the optical amplifier evaluating system of this invention can accurately obtain the gain G and noise figure NF of the optical fiber amplifier.

摘要翻译： 在本发明的光放大器评估系统中，组合使用光调制器的脉冲方法和探针方法，以获得光纤放大器的增益G和噪声系数NF。 第一光调制器打开和关闭从第一光源输出的信号光。 光复用器多路复用由第一光调制器导通和关断的光信号和从第二光源输出的探测光。 由光复用器复用的该光信号被选择性地馈送到光纤放大器中。 控制器正确地切换光路开关，允许光谱分析仪测量（1）光纤放大器的探测光输入信号的光强度，（2）从 通过第二光调制器的来自光纤放大器的输出信号光处于OFF周期并且探测光被输出，并且（3）由第二光调制器提取的信号光的区域中的光强度处于OFF周期 并且不会输出探测光。 基于测量光强度（1），（2）和（3），控制器计算光纤放大器的增益G和噪声系数NF。 以这种方式，本发明的光放大器评估系统可以准确地获得光纤放大器的增益G和噪声系数NF。

公开(公告)号：US5960134A

公开(公告)日：1999-09-28

申请号：US980688

申请日：1997-12-01

申请人： Hideyuki Sakamoto ,  Hiroshi Komazawa

发明人： Hideyuki Sakamoto ,  Hiroshi Komazawa

IPC分类号： G02B26/08 ,  G02B6/35 ,  G02B6/26

CPC分类号： G02B6/359 ,  G02B6/3504 ,  G02B6/3512 ,  G02B6/3548

摘要： To know an optical path switching error, a stepping motor is rotated at a predetermined angular step so as to couple an optical fiber collimator attached to its rotating shaft to an optical fiber collimator of optical fiber collimators that is designated by a designation signal. The direction of the optical axis of the optical fiber collimator is detected by a slit disk attached to the rotating shaft, and sensors for detecting slit arrays formed in the slit disk. Detection signals from the sensors are determined to correspond to the designation signal.

摘要翻译： 为了知道光路切换误差，步进电动机以预定的角度位置旋转，从而将附着在其旋转轴上的光纤准直器耦合到由指定信号指定的光纤准直器的光纤准直器。 光纤准直器的光轴的方向由安装在旋转轴上的狭缝光盘和形成在狭缝盘中的狭缝阵列检测用传感器检测。 来自传感器的检测信号被确定为与指定信号相对应。

公开(公告)号：US5210657A

公开(公告)日：1993-05-11

申请号：US834168

申请日：1992-02-11

申请人： Hiroshi Komazawa ,  Fuminobu Ito ,  Kenichiro Umesaki ,  Yuuichi Watanabe ,  Yoshiharu Sasaki

发明人： Hiroshi Komazawa ,  Fuminobu Ito ,  Kenichiro Umesaki ,  Yuuichi Watanabe ,  Yoshiharu Sasaki

IPC分类号： G02B26/02

CPC分类号： G02B26/02

摘要： A first optical attenuation filter is arranged in a predetermined optical path and attenuates light to be attenuated with a first variable attenuation amount. A second optical attenuation filter is arranged in the predetermined optical path and attenuates, with a second variable attenuation amount, the light which has been transmitted through the first optical attenuation filter. The first and second optical attenuation filters can be driven in the forward and reverse directions and each has an attenuation amount characteristic which changes monotonously in both the forward and reverse directions. An attenuation amount setting section sets a desired attenuation amount to the light to be attenuated. First and second drivers are coupled to drive the first and second optical attenuation filters in the forward and reverse directions, respectively. A controller controls driving directions and driving amounts of the first and second optical attenuation filters through the first and second drivers in accordance with the desired attenuation amount so that an algebraic sum of the first and second attenuation amounts finally becomes equal to the desired attenuation amount and a variation in attenuation amount is decreased as a whole, thereby providing a smooth attenuation characteristic.