SYSTEM AND METHOD TO MINIMIZE NONLINEAR DISTORTION IN LIGHT COMMUNICATION SYSTEM BY LASER INTENSITY MODULATION

摘要

PROBLEM TO BE SOLVED: To suppress the increase of power consumption and the increase of shot noises of a photoelectric detector by controlling the saturating point of a laser diode and the deflection of the broad-band multiplexed signal exceeding the upper and lower current limit values of the threshold-value current. SOLUTION: Base-band-frequency modulated television channels 12, 14 and 16 are coupled to one line as the multiplexed input signal Im(t). The multiplexed input signal Im(t) is received by an amplitude limiter 20. In the amplitude limiter 20, laser intensity modulation is performed by setting the mower number to the higher number so that a broad-band signal Ic(t) is contained in the linear region, the intrusion of the broad-band signal Ic(t) into the nonlinear region is performed and the nonlinear distortion is removed. The broad-band signal Ic(t) is supplied to a laser diode 22 as a part of the total laser driving current I and further sent to an optical fiber 24.