Hello Physics Stackexchange,
I'm currently working on a project with 1W 365nm UV LEDs, similar to this item. I'm using it to make some markers light up in a dark room. The problem is that aside of shining with the proper UV-A and creating expected lightning effects, the LED gives off a noticeable amount of visible light, which is not acceptable.
My question is, is there a dirt-cheap material that I can use in my project to block all/nearly all the visible light? I don't mind the filter cutting off a lot of the UV too, as I can increase power to the LED quite liberally. I can accept any DIY solutions and have access to a decently equipped workshop. Proper UV-pass camera filters seem far beyond my budget.
This is my first Stack Exchange question, so if there are any issues with it I'm eager to correct them once notified. Thanks!