OPTICAL SYSTEM FOR WAVELENGTH MULTIPLEX MODULATION

摘要

PURPOSE:To simplify a system by using an ultrasonic deflecting element using the acoustooptic effect to make it possible that signals independent of each other are put on rays different in wavelength directly without converting optical signals to electric signals in case of wavelength multiplex communication. CONSTITUTION:A wavelength multiplex light having wavelengths lambda1 and lambda2 propagated in the first transmission optical fiber 1 is radiated from the end face of the optical fiber 1 and is converged by a converging lens 2 and is made incident on an ultrasonic optical deflecting element. Oscillation levels of oscillators 5 and 6 are modulated independently and are applied to an ultrasonic transducer 4 of the ultrasonic optical deflecting element and an ultrasonic wave bundle 14 is propagated in an acoustooptic medium, and a diffracted light 11 is generated by the acoustooptic effect. At this time, optical wavelengths lambda1 and lambda2 and ultrasonic frequencies f1 and f2 satisfy relations lambda1f1=lambda2f2. Consequently, the diffracted light 11 has two wavelengths lambda1 and lambda2 modulated by signals inputted from modulating signal input terminals 7 and 8. Thus, the transmitted two-wavelength multiplex light having wavelengths lambda1 and lambda2 is modulated newly independently.