Sigurthr
0
- Joined
- Dec 11, 2011
- Messages
- 4,364
- Points
- 83
Re: Possible cheap 2-line 980nm/490nm pen
Remember that the eye is far less sensitive to the second harmonics of the lower IR/NIR wavelengths as well. doubling 780 would result in 365nm which while still visible, requires mW for even dark adapted eyes to see, where as 490nm can be seen in the uW range.
You'd need specialty dichroic/notch/pass filters and a photomultiplier detector to really test for spurrious emision like what we'd need. Still though, good experimental effort.
Remember that the eye is far less sensitive to the second harmonics of the lower IR/NIR wavelengths as well. doubling 780 would result in 365nm which while still visible, requires mW for even dark adapted eyes to see, where as 490nm can be seen in the uW range.
You'd need specialty dichroic/notch/pass filters and a photomultiplier detector to really test for spurrious emision like what we'd need. Still though, good experimental effort.