公开(公告)号：US4979825A

公开(公告)日：1990-12-25

申请号：US337741

申请日：1989-04-13

申请人： Katsushi Iwashita

发明人： Katsushi Iwashita

IPC分类号： G01J9/02 ,  G02F2/00 ,  H04B10/67 ,  H04B10/69

CPC分类号： H04B10/69 ,  G01J9/02 ,  G02F2/00 ,  H04B10/676 ,  G01J2009/0226

摘要： A system for a Mach-Zender interferometer which eliminates amplitude modulation of the input light and determines the frequency modulation. Two photodetectors in series are used to receive two outputs of two arms of a Mach-Zender interferometer. The outputs of the photodetectors are summed. The path length difference is controlled by a heater which itself is controlled by a controller. The controller selectively controls the heater based on how much non-zero components are present in the output of the photodetectors.

公开(公告)号：US5896216A

公开(公告)日：1999-04-20

申请号：US671819

申请日：1996-06-25

申请人： Koji Kikushima ,  Nori Shibata ,  Kouichi Suto ,  Katsushi Iwashita ,  Satoshi Ikeda ,  Hiroshi Nakamoto ,  Chisei Kishimoto ,  Kiyomi Kumozaki ,  Naoya Sakurai

发明人： Koji Kikushima ,  Nori Shibata ,  Kouichi Suto ,  Katsushi Iwashita ,  Satoshi Ikeda ,  Hiroshi Nakamoto ,  Chisei Kishimoto ,  Kiyomi Kumozaki ,  Naoya Sakurai

IPC分类号： H04N7/22 ,  H04B10/04

CPC分类号： H04N7/22

摘要： The AM/FM converter of the present invention comprises an optical frequency modulation section which receives multi-channel AM video signals and outputs an optical-frequency-modulated optical signal beam; and an optical heterodyne detection section comprising an optical frequency oscillator composed of a semiconductor local laser which outputs a local oscillator optical beam having an optical frequency separated by a designated intermediate frequency, an optical coupler, and a photoelectric converter composed of a photodiode, which receives the optical signal beam and outputs an electrical batched FM modulation signal which is frequency-modulated and frequency-converted to the intermediate frequency. By means of this configuration, the invention offers an AM/FM converter wherein the frequency band is made considerably wider.

摘要翻译： 本发明的AM / FM转换器包括光频调制部分，其接收多声道AM视频信号并输出​​光调制光信号光束; 以及光学外差检测部分，包括由半导体局部激光器组成的光频率振荡器，所述半导体局部激光器输出具有由指定中间频率分开的光频的本地振荡器光束，光耦合器和由光电二极管组成的光电转换器，所述光电转换器接收 光信号光束并输出被频率调制并频率转换为中频的电批量FM调制信号。 通过这种配置，本发明提供一种AM / FM转换器，其中使频带变得更宽。