| 摘要 |
PROBLEM TO BE SOLVED: To provide optical transmitters each of which has communication security and secrecy and immunity to an optical noise and which are used in coexistence. SOLUTION: The optical transmitter having a modulation means that encodes an information signal, a spread modulation means that applies spread processing to the encoded information signal to have a bandwidth wider than its required bandwidth by using a spread code, and a transmission means that transmits the information signal subjected to the spread modulation by means of infrared ray or a laser beam and the optical transmitter having a reception means that can receive the infrared ray or a laser beam including the information signal subjected to spread modulation by using the spread code, an inverse spread modulation means that restores the information signal received by the reception means to the original modulation signal by using the same spread code, and a demodulation means that restores the encoded information signal in existence in the restored modulation signal by the inverse spread modulation means to the original information signal, can make transmission reception. |
