Optical multiplex transmission system

Abstract

Abstract PURPOSE:To improve the degree of multiplex and communication speed by using a chirp pulse to narrow the pulse width of a received optical pulse. CONSTITUTION:Semiconductor lasers 4-1-4-3 generate the chrip pulse the wavelength of output light of which is changed in response to the change in the injected current and in which the generation of the spurious longitudinal mode is suppressed. When an optical pulse having a negative wavelength dispersion coefficient and the wavelength of which is changed at the leading edge and trailing edge is transmitted to an optical fiber 7, a pulse having a sharp waveform is obtained. Since the output light of the lasers 4-1-4-3 is generated where the phase is shfted little by little and a part of the phase is overlapped, a waveform like that of a multi-value pulse is obtained by synthesizing the pulse at a wave synthesizer 5. When an optical pulse signal propagates in the fiber 7, the peak part of the laser output light is squeezed forward to form a sharp waveform and a separated waveform possible for discrimination is obtained at the receiving output side.

Inventors

• 👤 Katsu Iwashita
• 👤 克 岩下
• 👤 Seiji Nakagawa
• 👤 清司 中川
• 👤 Kazuo Hagimoto
• 👤 萩本　和男

Bibliographic Details