Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Hiroaki Sanjoh

Masahiro Endo

Masatoshi Tobayashi

Shinsuke Nakano

Masafumi Nogawa

Yoshikazu Urabe

Eiichi Yamada

Yuzo Yoshikuni

An amplifier typically exemplified by a TIA is realized that provides an optimal band characteristic, that reduces the possibility of the oscillation, and that achieves a reduced dispersion of the band characteristics. An amplifier for amplifying an electric signal, comprising: a first buffer for amplifying the electric signal; a filter that is connected to an output of the first buffer and that includes a parallel circuit consisting of an inductor and a first capacity; and a second buffer connected to an output of the filter.

Amplifier

There is provided a WDM optical transmission system and transmission method that have excellent spectral efficiency. The WDM optical transmission system is provided with: an optical transmitting section having an optical transmitter that generates N wave (wherein N is an integer of 2 or greater) optical signals with an optical frequency spacing &#x394;f [Hz] and modulated by a modulation bit rate B [bit/s] (wherein B/&#x394;f&#x2266;1 [bit/s/Hz]) using a modulation device, and having a coupler that couples the optical signals; an optical receiving section provided with an optical DFT circuit of a sampling frequency &#x394;f [Hz] that is equal to the optical frequency spacing; and a bit phase adjustor that makes bit phases of respective wavelength division multiplexed signals synchronous at an input of the optical DFT circuit.

Wavelength division multiplexing optical transmission system and transmission method

Growing community of inventors

Atsugi, Japan

Hiroaki Sanjoh