Optimum operating voltage test method of avalanche photodiode

Abstract

The invention discloses an optimum operating voltage test method of an avalanche photodiode. The method includes the following steps that a micro-control unit outputs a direct current control signal; a bias voltage corresponding to the direct current control signal is applied to the avalanche photodiode; a timer achieves delaying by first preset duration; dark current flowing through the avalanche photodiode is collected within first timer interrupt after delaying is finished; the micro-control unit judges whether the dark current reaches reverse breakdown current or not; if the dark current reaches reverse the breakdown current, the optimum operating voltage of the avalanche photodiode is calculated out according to the value of the bias voltage; if the dark current does not reach the reverse breakdown current, the direct current control signal is updated, and the steps that the micro-control unit outputs a direct current control signal and a bias voltage corresponding to the direct current control signal is applied to the avalanche photodiode are carried out again. By means of a time slice rotation mode, in the delaying process of the timer, a main operating cycle of the micro-control unit can perform other operating tasks and other corresponding interruption work, and production test efficiency is improved.

Description

technical field [0001] The invention relates to the test of electric variables, in particular to a test method for the optimum working voltage of an avalanche photodiode. Background technique [0002] Today, with the increasing development of optical communication, the demand for avalanche photodiode (APD tube) optical devices is also showing rapid growth. Therefore, improving the production and testing efficiency of APD tubes, accurately and quickly finding its optimal working voltage, and reducing its production and testing time have become the key factors to increase production capacity and reduce costs. [0003] The key link in the production of APD tube optical devices includes finding the best working voltage of the APD tube. The APD tube needs to work under the reverse voltage of 30-60V. Under the optimal working voltage, it will produce an avalanche effect, which doubles the photoelectric conversion efficiency, thereby improving the receiving sensitivity of the opti...

AI Technical Summary

Problems solved by technology

However, in this adjustment method, the micro-control unit continuously executes the adjustment action in the adjustment process, and cannot respond to other tasks in real time.

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