The Experimental Study On 1/f Noise Of Semiconductor Laser

The interior noise of semiconductor laser,especially low-frequency noise of it is a key guideline restricting the sensitivity and the inspecting accuracy of electronic devices including semiconductor components and integrated circuits. It is also a sensitive parameter depicting the quality and reliability information of these devices.It is a good method to evaluate the devices' reliability by testing and analyzing inner noise.However,traditional method is by aging, even though it is effective,but long time,expensive and is harmful.So nowadays testing low-frequency is becoming a new method as it is quick, economic,useful.This article is involved in the experimental study of low-frequency 1/f noise of semiconductor laser.After reviewing briefly of the development and the significance of low-frequency noise,this article introduces the operating principle of semiconductor laser,the mathematical theory of noise and the components of semiconductor devices.The low -frequency noise of semiconductor laser include 1/f noise and g-r noise,and in a large range they added.Some objections of semiconductor laser can cause 1/f noise and g-r noise.In this paper,introduces the hard-system and soft-system in details which are required in the experimental design.And,the hard-system is focused on digital spectrum analyzer,with current meter,noise source,current adjusting, amplifier,and PC.The noise data is collected from the spectrum analyzer, send to PC in order to progress.There are many data that the current is between 0.0074mA and 100mA,frequency is between 1.25HZ and 658.7497HZ.Then use the software NoiseCurvenihe get three important parameters of 1/f noise,in order to study the 1/f noise.NoiseCurvenihe soft-system is designed by the developing language VC++ and finally meets with the requirement.This article mainly do study on the three parameter characterizations of 1/f noise- white noise amplitude,1/f noise amplitude,frequency exponent gene, and different graphs,which is based on the adequate noise data.From the experiment,we get that the value frequency exponent gene mainly remain around 1.0.The graph shows that with the increase of current,white noise amplitude is rising at first,and drop at 0.04mA dramatically to a low leave. The 1/f noise amplitude change with frequency is accord with theory,that drop gradually.And with the increase of current,different graphs' peak is decline. The 1/f noise amplitude change with the increase of current is increase first and falls to a low value,as the same as the graph of 1/f noise amplitude-current.So the graph of 1/f noise amplitude can reflect the power density of 1/f noise.With the increase of current,different power density graphs' peak is fall down.Based on the noise parameter graphs and the circuit theory of semiconductor laser,I study of the producing mechanism of 1/f noise. In conclusion,when current is small,1/f noise is mainly come from no resource area and 1/f noise amplitude is direct ratio to current's square;when current increase gradually and become big,1/f noise is mainly come from resource area and amplitude is direct ratio to minus current.