Recommended · for advanced
Laser diode self-mixing: Range-finding and sub-micron vibration measurement
Why people recommend it
Applied Science uses a laser diode's built-in monitor photodiode for self-mixing interferometry, measuring distance and sub-micron vibration; cited when people ask about the third pin.
In their words
I would try this self-mixing method using a laser diode with integrated photodiode:
DKNguyen on electronics.stackexchange.com, May 2022. CC BY-SA.
If you are curious, here is a video by Applied Science that is very interesting.
Andrew Cline on electronics.stackexchange.com, Nov 2023. CC BY-SA.
Applied Science looking at vibrometry using laser diodes:
user1850479 on electronics.stackexchange.com, May 2021. CC BY-SA.
