Question: If you were to create coloured lasers what would they look like ?

Padraic Morrissey answered on 31 Jan 2015:

The funny thing about the lasers I work with is that you can’t see them with your eyes at all! It’s a bit like a dog whistle. If somebody blows into one of those, dogs can hear it but we don’t hear anything. That’s because there are only certain frequencies our ears can pick up on. The same happens with light from a laser. Our eyes are designed to see a particular set of colours, which have certain frequencies. If a beam of light is at a lower or higher frequency than what we can see, it has no colour and it looks invisible!

Some people work on red lasers, which we can see easily, but the lasers I design are really far beyond what our eyes can make out. To see the light from my lasers I need expensive equipment which is far more sensitive to light than a human eye. This light can have a mixture of different colours, but we use numbers to describe them.

Hope that answers your question, let me know if you’d like me to explain anything else!