Nippon Telegraph and Telephone Corporation

Hiroshi Yasaka

Shoichi Sudo

Yoshihisa Sakai

Itaru Yokohama

Kenichi Kubodera

Yuzo Yoshikuni

Tetsuhiko Ikegami

Masahiro Ikeda

Mitsuru Naganuma

Shingo Uehara

Osamu Mikami

Katsuhiko Kurumada

A wide band distributed Bragg reflector having a reflectivity extremely greater than that of a narrow band distributed Bragg reflector mirror portion on the output side of a bistable type wavelength conversion device is arranged on the incident side. The input light in TM polarization mode is used as an input signal light and the wavelength conversion is performed by tuning the narrow band distributed Bragg reflection mirror portion on the output side from which an output light in TE polarization mode outgoes perpendicularly to the input light. The input signal light and the output signal light are polarized in such a manner that they are perpendicular to one another and, therefore, the device can be realized as a one-directional device. The use of any isolator is not required.

Semiconductor wavelength conversion device

A method of stabilizing the frequency of a semiconductor laser comprises stabilizing a time-dependent frequency fluctuation by utilizing an optical energy absorption medium including an isotope acetylene gas molecule. An apparatus for stabilizing the frequency of a semiconductor laser, comprises a semiconductor laser, an optical energy absorption medium, a photodetector and a control circuit as essential elements. The optical energy absorption medium includes an isotope acetylene molecule.

Method and apparatus for stabilizing frequency of semiconductor laser

Growing community of inventors

Zama, Japan

Hiroshi Yasaka