Modern printed laser modulation

The laser can be used as a tool for transmitting information. The process of loading the information to be transmitted (digitalized image and text) into laser radiation is called laser modulation. Since the laser functions to “carry” information, it is called a carrier wave. Commonly used in print printing are electro-optic modulators and acousto-optic modulators. In practical applications, most of the acousto-optic modulators are acousto-optic modulators. The acousto-optic modulator consists of an acousto-optic medium, an electro-acoustic transducer, a sound-absorbing device, and a driving power source. The acousto-optic medium commonly used in printing equipment is molybdenum. Lead (PbMoO4) crystals. The electro-acoustic transducer piezoelectric crystal is lithium niobate (LiNbO3), which utilizes the reverse piezoelectric effect to generate an ultrasonic field under the action of an applied electric field to form an ultrasonic field and to convert the modulated electrical signal into an acoustic signal. The operation of the laser is driven by the modulation power supply. When the laser passes through the acousto-optic medium, Bragg diffraction occurs due to the interaction between the light and the acoustic field, and the first-order diffracted light is output as the output. When the amplitude of the acoustic wave changes with the modulation signal, the intensity of the diffracted light will change accordingly. The output light is periodically modulated light.
Here, the modulator also serves as an electro-optic switching device in the optical path system, that is, converts the electrical information signal of the graphic and text output by the computer into an optical signal.