When you start mentioning laser guns, it’s easy to think Star Wars. But the technology has been around for years, and new applications for the use of laser are found all the time. Now a small team of Norwegian inventors have taken lasers to new heights – or rather new depths. They have built underwater laser guns to target a small parasite threatening the country’s vast fish farming industry. I went to find out more and made this report for Spectrum on Deutsche Welle Radio.