Recently, we have bought a VCSEL laser diode, in which we can vary the wavelength by tuning the voltage and/or tuning current. Also, we got an application note in which it states as follows: "Set a current limit to 100 uA". I assume that this is a current limitation of wavelength tuning current.
However, How do I limit the current based on the pin diagram? Screenshots are given below.
How do I limit the current based on the pin diagram?
You don't. You use the features of the circuit that is supplying the pin to limit the current.
For example, you use a benchtop supply with a current limit function.
The instruction is probably meant only to describe benchtop testing, where it's easy to make a mistake in the connection polarity, etc. For your final circuit you might not need this limiting capability (but it would be a good idea to confirm this with the vendor).
