How to use light-emitting diode and photodiode together?

When I connect light-emitting diode (port W) to photodiode (Port D) in simulink, errors will occur. It says 'Invalid Physical Signal connection at port 'W'. Source unit is 'W' and destination unit is 'W/m^2''' What do I need to insert between light-emitting diode and photodiode? Thanks!

[Daniela Corral]

Do you already know how to do it? Because I have the same problem :(

Answer 1

[vaibhav singh]

pls answer