There's an easy way of blocking the visible part of your laser. Use a piece of exposed photographic film, like the beginning of a roll of negatives, you know, where the negative is all black. Use several layers if necessary. The film will block most of your blue or green light, yet let the IR light through. The problem is, it'll let both 808 and 1064nm through, so you can't have an accurate reading for each wavelength, but at least you'll know if your laser is producing IR. Another potential problem with this approach is that the laser, if powerfull enough, may melt the plastic and render this procedure useless.
In case someone doesn't have a laser check, you can use a digital camera with night vision capability, like the handycams. Put it in nightshot mode, put several layers of the film in front of the laser and point it towards a wall, where the camera might see the IR beam. Don't point your laser towards the camera, as you may burn some pixels on the CCD.
Just my $.02 on this subject
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