How to Measure Laser Exposure/Dosage

July 6, 2016

OphirBlog

Usually, I talk about measuring power or energy. Today I want to discuss exposure – total energy deposited over time.

Why Measure Exposure?

This is the important parameter in certain applications, specifically photolithography and UV curing.In these applications, the instantaneous power of the CW beam is less important than the total exposure or dosage that the work piece got.

How to Measure Exposure?

Theoretically, a regular power meter plus a stopwatch should do the trick. However, in order to make the measurement process easier, not to mention more precise, we added a feature to our newest StarBright meter to support exposure measurement with a photodiode sensor.

There are two ways to measure exposure: manual and timeout.

Manual Exposure Measurement

Step 1.            In the StarBright menu, select “Exposure Mode.”
Step 2.            Press “start” when you would like to begin measuring.
Step 3.            Press “stop” when you would like to end the measurement.

Timed Exposure Measurement

Step 1.            In the StarBright menu, select “Exposure Mode.”
Step 2.            Select “Timeout” mode
Step 3.            Use the arrows to select the timeout interval
Step 4.            Press “start” when you would like to begin measuring. (StarBright will automatically end the measurement when the timeout is reached.)