Yeah I could use my phone's camera to see if it's on. I'm being a little hyperbolic because there is a cooling fan that would always be on if the laser is on. So I would know if it's running.

Fun fact though, pretty much every digital camera can see IR without modification. Honestly, this whole discussion of IR has me looking at getting a diode and building a driver. I didn't know those diodes were so cheap. 😅