Research On 1064nm Millisecond Pulse Laser Interaction With Silicon-based Quadrant Photodetector

Photo-detectors have applied in many fields,so the laser irradiation effect on semiconductor materials and semiconductor photodiode have become an major project.When laser interact with a photo-detector,the parameters and performances of the photo-detectors can be affected.In the process of a photo-detector being irradiated by a millisecond pulse laser,the study of thermal and electrical effects are most important.A silicon-based quadrant photo-detector(QPD)is taken as the research object,and the damage process,law and mechanism of a 1064 nm millisecond pulse laser interaction with a silicon-based QPD is studied respectively from three aspects,theoretical research,simulation research and experimental research.Specific research contents are as follows,On the theoretical part,the electrical and thermal models of the process of a 1064 nm millisecond pulse laser interaction with a silicon-based QPD are established.In terms of the electrical model,it includes the electric field model and the output current model,therefore,the electric field and the output current are described,and the output current is divided into the initial stage,the maintenance stage and the relaxation recovery stage.The thermal model of the process of the 1064 nm millisecond pulse laser interaction with a silicon-based QPD is perfect.The laser heat source,Joule heat source are considered,and Thomson heat caused by temperature gradient in current density is taken into consideration.It provides a theoretical support for the phenomenon of the maximum surface temperature for a silicon-based QPD decreases with the increase of bias voltage.Based on the theoretical model,the electrical simulation model and thermal simulation model of the process of a 1064 nm millisecond pulse laser interaction with a silicon-based QPD are established.Through electrical simulation research,the variation rule and trend of electrical parameters are obtained,the electric field increases as bias voltage and temperature in a QPD.In the cell for a silicon-based QPD irradiated by laser,there are initial stage,holding stage and relaxation recovery stage in the output current curve,and holding stage shows a decreasing trend over time,while the relaxation recovery stage shows a fluctuating trend.Output current of other three cells curves also exist in the above three stages with different trend.Through the thermal simulation research,the variation of thermal parameters are obtained.Under the same laser parameters and bias voltages,the maximum surface temperature for each cell decreases with the increase of the distance from the center of the laser beam to the cell.Under the bias voltage and laser pulse width,the maximum surface temperature increases with laser power fluence.Under the bias voltage and laser energy fluence,the maximum surface temperature increases with laser power fluence.Under the same laser parameters,the maximum surface temperature decreases with the increase of bias voltage obviously.The experimental system corresponding to the 1064 nm millisecond pulse laser interaction with a QPD are constructed,including temperature measurement system,output current measurement system,dark current measurement system,damage area and damage morphology measurement system.The temperature output current in the QPD change with bias voltage,laser pulse width and energy fluence are obtained,and the relationships between the dark current,damage area and damage morphology with laser energy fluence and pulse width are also obtained.The experimental results are in good fit with the simulation results.The simulation model can reasonably describe the process of a 1064 nm millisecond pulse laser interaction with a QPD.Take the experimental results of 2.0 ms as an example,for the result of the maximum surface temperature and output current,the mechanism of the process of a 1064 nm millisecond pulse laser interaction with a QPD under bias voltage is given when the QPD is without damage.Combined with the results of the maximum surface temperature and damage morphology,the damage mechanism of the process of a 1064 nm millisecond pulse laser interaction with a QPD under external bias voltage is given.