Nippon Telegraph and Telephone Corporation

Ken-ichi Suzuki

Masamichi Fujiwara

Katsumi Iwatsuki

Noboru Takachio

Masatoshi Saruwatari

Yoshitada Katagiri

Shigendo Nishi

Fumikazu Ohira

Shinji Nagaoka

The present invention provides a light generation method and a light source that are preferable in obtaining a single-mode light having high outputs, a small wavelength spectral bandwidth, and a low intensity noise. A white output from a white-light source and having wavelength components over a wide-band in a wavelength spectrum passes through an isolator and is then filtered by a disc-shaped optical filter. A transmitted light is input to a semiconductor optical amplifier having its polarization plane regulated by a polarization controller. An output from the amplifier passes through an isolator and is then filtered by a disc-shaped optical filter again to generate a single-mode light having a small spectral bandwidth and high outputs. Polarization control by the polarization controller corresponds to control of the polarization plane of a semiconductor laser in the semiconductor optical amplifier so as to obtain a maximum gain from the amplifier. This configuration enables a single-mode light having a small spectral bandwidth and high outputs to be easily generated at an arbitrary wavelength.

Light generation method and light source

In the method of measuring a distribution of zero dispersion wavelengths in an optical fiber in a longitudinal direction, an optical pulse and a pump light are launched into the optical fiber. A gain generation portion of the optical fiber which indicates that the optical pulse power is amplified based on modulation instability induced by the pump light is detected from a back-scattered light waveform of the optical pulse indicative of an optical pulse power distribution in the longitudinal direction of the optical fiber. A zero dispersion wavelength of the gain generation portion of the optical fiber is determined from the pump light wavelength.

Method for measuring distribution of zero dispersion wavelengths in an

Growing community of inventors

Kanagawa, Japan

Ken-ichi Suzuki