Study On Optical Signal Modulation Technology Of Tomato Growth Induced By Laser

With the rapid development of agricultural production in our country,the way of laser irradiation plant growth is increasingly mature,especially people to eat vegetables and fruits.Chinese traditional laser inducement plant growth field is mainly He-Ne gas laser irradiation,irradiation mode is relatively single,promoting plant effect is not obvious,resulting in low seed maturity,seedling growth is not stable,causing unnecessary economic losses.The purpose of this paper is to study the modulation technology of the optical signal of the traditional semiconductor laser.The modulated system is applied to the tomato growth process,and the various indexes of tomato plants are improved to a certain extent.This research has great significance for the research of the optical signal modulation technology in the field of agricultural irradiation.In this paper,the semiconductor laser PLP B450 is modulated,and a complete set of optical signal modulation scheme is designed.The whole optical signal modulation system mainly modulates semiconductor laser by improving the hardware module.The whole hardware platform is mainly composed of STM32 as the main control chip,laser driving circuit,constant current driving power supply,automatic temperature control circuit,automatic power control circuit and OOK modulation circuit.By comparing the two laser modulation technologies,direct modulation mode is selected,and OOK(on/off control)is selected to realize the modulation output of the optical signal modulation system.According to the data and preliminary experimental data analysis,the simulated plant body information transfer model was established,which laid the theoretical basis for the subsequent laser induced tomato growth experiment.By modulating the optical signal of the PLP B450 semiconductor laser,the bandwidth of the modulated semiconductor laser is 35 MHz,the maximum optical power can reach 81.5m W,and the longest radiation distance is 80 m.After irradiation experiment,compared with the control group,the germination rate of 5.0m W·mm-2 experimental group increased by 6.7%,and the stem length of tomato seedlings on the 15 th day of growth increased by 7.7%.On the 27 th day,chlorophyll and carotenoid increased by 33.3%and 26.7% respectively.On day 30,peroxidase activity increased by 27.7%,isoenzyme activity increased by 69.7% and superoxide dismutase activity increased by 13.6%.According to the experimental data,it satisfies the simulated plant information transmission model.The light signal modulation system can effectively improve the survival rate of tomato seeds,increase the growth rate of tomato,accelerate the rate of photosynthesis,and enhance the expression of internal enzymes.The light signal modulation technology is beneficial to promote tomato growth,pave the way for the laser inducement plant growth of modern agriculture,promote the development of new agriculture and modulation technology.