Based On The Acoustic Transducer "cat's Eye" Reverse Light Modulation Technology And Application

The cat’s eye reversal modulator is based on the cat’s eye effect, mainly used in thefield of long-distance optical communication. In recent years, the considerabledevelopment has been made in new field for the development of piezoelectric materialand growing of optical modulation technology.The cat’s eye reversal modulation technology is applied in the field of signaltransmission and identification. In this article, the research of wireless optical signaltransmission technology and the supporting circuit have been made. The main researchcontents are as follows:1. The application of optical reversal modulator in wireless optical signaltransmission．(1) A theoretical model is proposed based on optical reversal modulator, by whichsome related theoretical results have been conducted: cat’s eye system has a goodoptical reverse performance no matter in coherent light condition (with Fourier method)or in incoherent light condition (with transfer matrix method). Further study of thedefocus type of cat’s eye system has been conducted that its reflectivity changes withthe defocus amount accordingly with varying distance, focus and detector’s size.(2) Based on theoretical researches have been conducted, experiments based oncat’s eye system with laser source have been carried out: firstly, experiments usingdefocus type cat’s eye reversal modulator have been designed and implementation hasbeen clarified. Then, overall construction of the system has been completed, includingthe design of the optical platform, driving circuits and signal processing circuits. Finally,experiments based on completed platform have been carried out; optical signal has beensuccessfully modulated through the circuit driving the cat’s eye’s system; the detectedsignal has been successfully demodulated by the signal processing circuits. System’stransmission speed is up to600bit/s, so the feasibility of applying the technology in IDrecognition has been verified.(3) In order to achieve the goal of lowcost, laser was replaced by infrared light, thestructure has been redesigned, the platform has been rebuild. Further related experiments have been carried out. At last the feasibility of the remote door-controlsystem based on cat’s eye system has been verified.2. The research of supporting circuit related to wireless optical door controlsystem(1) Supporting circuit of key has been obtained: The circuit which as the STC12C2052microcontroller as the core component has been designed and implemented.The piezoelectric chip be driven and modulated by this circuit. The control signal is(Password) stored in microcontroller and write or change password into microcontrollerare available.(2) Supporting circuit of lock has been obtained: The related information has beendemodulated by amplifying, filtering, and envelope detecting the signal received fromoptical detector. A series of actions like unlock or audible and visual alarm will be takenbased on the result of comparison. Writing or changing password into microcontrollerhave been achieved successfully.