| 摘要 |
PROBLEM TO BE SOLVED: To provide a light analog transmitter which does not deteriorate a carrier to noise ratio(CNR) of an intermediate frequency signal when a laser is directly modulated by a signal, which is the combines of an intermediate frequency signal and an unmodulated wave signal, and is transmitted to the transmitter from a transmission terminal station. SOLUTION: This device is a light analog transmitter which is equipped with a combining means 6 which combines an intermediate frequency signal modulated by information to be transmitted and an unmodulated wave signal being a sine wave, and a means 7 for subjecting the combined signal to electrical to optical conversion by direct modulation of a semiconductor laser diode with a resonance frequency fr and transmitting the result to an optical fiber 3. In this case, the condition that the frequency fIF of the intermediate frequency signal and the frequency fL0 of the unmodulated wave signal satisfy the conditions fL0 -fIF>=1 [GHz] and 2fIF<fL0 <(2/3).fr. |
