Method and device for monitoring input optical power of avalanche photoelectric diode

Abstract

The invention discloses a method and a device for monitoring the input optical power of an avalanche photoelectric diode, and provides a novel ROSA; a planar optical waveguide splitter splits a received input optical signal into two circuits, wherein one circuit of light with high optical power is distributed to the traditional avalanche photoelectric diode of an optical receiver and is applied to an original optical receiver, and the other circuit of light with low optical power is distributed to a linear photoelectric diode for improving the monitoring precision to the input optical power. The technical scheme can reduce the cost and the complicacy of a monitoring system to the input optical power of the traditional avalanche photoelectric diode in the optical receiver, and improve the monitoring precision to the input optical power.

Description

technical field [0001] The invention relates to the technical fields of optics and electronic engineering, in particular to a method and device for monitoring the input optical power of an avalanche photodiode. Background technique [0002] The traditional optical receiver monitors the input optical power of its APD avalanche photodiode by using the current monitor chip of the high-voltage power supply to measure the photocurrent Iapd flowing through the avalanche photodiode, that is, the output photocurrent Iapd of the current monitor chip Mirror the current Iapd1, and then use an ADC analog-to-digital converter to sample the mirror current Iapd1 and convert it into a digital quantity. In the case of different input optical power, by sampling different values ​​ADC_Iapd of the photocurrent Iapd flowing through the avalanche photodiode, a graph is formed, such as figure 1 , where the horizontal axis is the sampling value of the 12-bit ADC of Iapd, and the vertical axis is t...

AI Technical Summary

Problems solved by technology

However, because the avalanche photodiode is very sensitive to several external environmental factors such as Vapd bias voltage and ambient temperature, it is known that the Iapd photocurrent output by the avalanche photodiode is different under the same input optical power value but different Vapd bias voltage. The Iapd photocurrent output by the avalanche photodiode is also different under the same input optical power value and the same Vapd bias voltage but different temperatures, and the Iapd photocurrent value output by the avalanche photodiode under the same Vapd bias voltage and the same temperature The input optical power value is a non-linear relationship, and complex formulas are required to convert the Iapd photocurrent value (actually the digital quantity of the mirror current Iapd1) into the input optical power value

Therefore, the accuracy of traditional input optical power monitoring with avalanche photodiodes, according to the SFF-8472 protocol, combined with the test data of actual mass production, within the commercial temperature range of 0 degrees Celsius to 70 degrees Celsius, the error can only be controlled within + / -3dB , 3dB means that the difference between the monitored value and the actual value is half, which is an almost intolerable error for optical communication systems

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