Optical repeater

Abstract

Abstract PURPOSE:To increase the reliability of an optical repeater, by suppressing the output of the beam of a semiconductor laser by the function of a control circuit when the optical input level of the supplied optical time series digital information is less than a prescribed value and then actuating slowly the control circuit. CONSTITUTION:In case the optical level of the optical information supplied to an optical repeater 1 is less than the optical level which is necessary for the normal working of the repeater 1, a specific control signal affects a logical circuit 21 to prevent the electric information obtained from an identifying circuit 9 from being supplied to a driving circuit 10. At the same time, a control circuit 22 suppresses forcibly the bias current of a semiconductor laser 11 down to almost zero to a stabilizing circuit 12 that holds the optical output level of the laser 11 to avoid an output of the optical information from the laser 11. Furthermore, these functions are given gradually within a range less than the time required for switching of an optical switch and with a time constant larger enough than the time constant at the interstage coupling part of an amplifying circuit.

Inventors

• 👤 Toshinori Mori
• 👤 Norio Nishi
• 👤 Kyoichi Iwasa
• 👤 Shinji Nagaoka

Bibliographic Details