LIGHT WAVE COMMUNICATION SYSTEM HAVING SOURCE SYNCHRONIZED INDIVIDUALLY WITH OBSOLUTE FREQUENCY STANDARD

摘要

PURPOSE: To autonomously and locally attain accurate and instantaneous stability of a semiconductor laser by adopting an absolute frequency reference element to be driven through an optogalvanic effect in a feedback control loop having an individual laser. CONSTITUTION: When a laser 104 is biased to a lasing state, the laser 104 radiates an optical signal 107 of a characteristic wavelength generally known as optical luminescent wavelength λp . A gas discharge element 105 generates an electric signal to a lead 108 through the optogalvanic effect in response to the optical signal 107 radiated from the laser 104. The signal is supplied to an optogalvanic control circuit 106. The circuit 106 processes the electric signal, so that the wavelength of the laser 104 is controlled through a lead 109 so as to be matched with the absolute frequency reference set up by the atomic or molecular transition line of a gas sort in the element 105.