What is Response Time of a Photodiode?

1 Answer
Can you answer this question?

- GoPhotonics

Oct 3, 2023

The response time of a photodiode refers to the time it takes for the photodiode to generate a detectable electrical response to a change in incident light intensity. It quantifies the time taken by a photodiode to react to the variations in light and produce a corresponding change in its output current or voltage. Response time is a crucial parameter, especially in applications where rapid detection of light fluctuations is essential.

There are two primary components that make up the response time of a photodiode:

Rise Time (tr): The rise time is the time it takes for the photodiode's output current or voltage to increase from 10% to 90% of its final value in response to an increase in incident light intensity. It measures the speed at which the photodiode can respond to a sudden increase in light.

Fall Time (tf): The fall time is the time it takes for the photodiode's output current or voltage to decrease from 90% to 10% of its final value in response to a decrease in incident light intensity. It measures the speed at which the photodiode can respond to a sudden decrease in light.

The total response time (ttotal) of a photodiode is often expressed as the sum of the rise time and fall time: