| Semiconductor lasers (LDs) as a kind of important light source are widely used in optical fiber communication, optical sensor, information memory, medical treatment, pumping solid lasers and optical fiber amplification. The quality and reliability of semiconductor lasers is imperative in all the applications. At present, the usual method of screen is electric aging by increasing the temperature and aging current to measure LDs threshold, quantum efficiency and output power. The result of aging is statistic, and the time is long, and the method is not sensitive for potential defects. During the aging, the lifetime of the reliable devices is also affected. Thus, it is significant to find a kind of a fast, nondestructive, convenient method to test the devices and estimate their reliability. The electric noise in semiconductor devices, which reflects the quality and reliability of device, can be used to detect the reliability of device. At present, this method is applied in bipolar transistor, Zener diode, GaAs MESFET. In recent years, we research the relation between noise and the quality and reliability of semiconductor laser. In this paper, it's summarized that the math basis of noise and the variety,characteristics and producing mechanism. It's given that the noise test method and test system used in experiment. Based on the theory and test system, we research the electric noise of semiconductor lasers after annealing and the relation between the change of electric noise characteristic and the reliability of device. It's also discussed that the relation between electric noise and technics of bipolar transistor. Electric noise is the fluctuation of output voltage of semiconductor device. The noise is figured by measuring frequency spectrum density in experiment. The background noise should be low enough since the noise of semiconductor laser is very weak. We adopt the direct measure and cross-spectrum measure technology, which lower the background noise of system. The noise before and after cross-spectrum are 1nV/Hz1/2 and 0.1nV/Hz1/2 respectively. The samples are screened triply to control the external disturbing , and the multi-grounding is adopted to avoid electromagnetic disturbing. The direct current power supply isn't fit for the noise test because the fluctuation of output current will reflect the noise of device. We adopt large capacity battery(continuously work 7h at 1A) which can fulfill big output current and low noise to avoid disturbing。The devices used in the experiment are 808nm GaAs/GaAlAs semiconductor lasers. At temperature (18±2) ℃, the electric derivative and the low frequency electric noise of devices are measured. The test processes are repeated after aging test at 0.5A. It's found that the electric derivative curve of some device turned to be bad, but the noise frequency spectrum density decreased. Generally, the initial noise of good device is lower and change little after aging, and the initial noise of bad device is higher and increase obviously after aging. In the experiment, we found that the noise of bad device decreased by contraries。That's because the structure of 808nm is GaAs/GaAlAs, and there exists REDR(Recombination Enhanced Defect Reactions)effect which make the defect acquire power and quicken the movement in Ⅲ-Ⅴmaterial. Moreover, some defects are annealed to stable state for the aging condition that the temperature(18±2) ℃and 0.5A aging current is the annealing process for devices. Though the noise of devices decrease, the quality of devices still fail. That's because the initial defects producing at high temperature still exist. The research illuminates:The annealing effect will appear at some aging current. The noise of bad devices decreases after aging. By comparing the initial noise and the decline rate after aging can eliminate the failed products. The results are important for learning the characteristic of noise and correct the noise test criterion。...
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