Research On Key Technologies Of R/G/B Laser Diode Hybrid White Light Communication

R/G/B laser diode(Laser Diode,LD)mixed white light illumination was to form R/G/B LD with a certain power ratio to form standard white light that can be illuminated.Due to the high coherence,large bandwidth capacity,high output power and low noise of amplified spontaneous emission(ASE)of LD,the use of LD instead of LED can effectively enhance the transmission capacity of the optical system.This article mainly studies R/G/B LD mixed white light communication,using R/G/B LD mixed white light for illumination and data transmission.The main research work was as follows:1)The principle of R/G/B LD mixed white light was analyzed.First,the characteristics of the white light spectrum model were described,and then the white light illumination quality evaluation parameters were analyzed.Finally,the calculation method of the laser diode optical power was given to provide a theoretical reference for subsequent research.2)Proposed hybrid white light driving technology for laser diodes.First,analyze the principle of time-division multiplexing technology,design an FPGA module,and simulate the timing diagram of the time-sharing transmission of the module to realize the time-sharing transmission of information.Then analyzed the current and temperature characteristics of the laser,designed a constant temperature and constant current module and performed a performance test on the module.Finally,the LD current characteristics were analyzed,and the LD modulation module was designed,and its performance was tested and analyzed.The experimental results show that the module realizes the modulation of information.3)The circuit design of the receiving end of the hybrid white light communication was studied.The APD(Avalanche Photo Diode,APD)multiplication and bias characteristics were analyzed,the APD experiment platform was built,and the APD modulation characteristics were tested.The influence of the photodetector on the conversion of electrical signals was analyzed,and the pre-amplifier module and main amplifier module were designed and made.4)The influence of different diffusers on the transmission performance of R/G/B LD mixed white light illumination was studied.The color transmittance,surface roughness,CCT(correlated color temperature,CCT)uniformity,divergence angle of the diffuser and other characteristics of the six diffusers were analyzed.When the CCT was 6500K,the six diffuser pairs were verified.The effect of R/G/B LD mixed white light beam transmission performance,the experimental results show that the frosted glass(FG_2.8)has the highest transmittance for white light scattering among the six diffusers,and the divergence angle was±20°.5)Analyzed the impact of sampling rate on R/G/B LD mixed white light information.Due to the influence of the low APD bandwidth receiving performance,the sampling interval was set to 3?25GS/s.The experimental results show that the sampling rate was 3GS/s.At s,the SNR and BER of the received information were the lowest.