Cloudray 900-1600nm IR Infrared Laser IR Detection & Alignment Visulizer Detector Display Board Card B Type Visualizer Board(60x20x3mm)

I'm reviewing the 60mm x 20mm version of this product.The description says "The effective sensible area is 60 x 20mm, not the whole board." Since the board's DIMENSIONS are 60mm x 20mm, I wasn't sure what to expect.I received a featureless white 60mm x 20mm ceramic slab in a plastic bag, with no instructions or documentation. I tried various IR sources on it, and didn't see any visible effect at all. I finally got some green fluorescence with ONE of my emitters.Here's what I've figured out after a fair amount of experimentation:1) The board is NOT sensitive to IR light in the 800nm-850nm range, which is apparently what most of my sources produce. Those sources produce no luminescence at all. Fair enough; the description clearly says "900-1600nm".2) Only a limited area of one side of the board is sensitive. If you look carefully at the product photo of the 60mm x 20mm board, you can see that the right-hand portion of the board is ever so slightly lighter than the left-hand portion. This lighter portion, barely noticeable to the naked eye, is the sensitized part. It's very difficult to see which part is sensitive.3) That limited sensitized area DOES glow green when hit with longer-wavelength IR. I have one source that I believe is 950nm, and that does produce a green spot on the board.I'd be happy with this item if:1) the description were accurate (describing the size of the sensitive area, and that it's only on one side of the board), and2) the sensitive area were MARKED on the board (why make a 60mm board if only 25mm of it is sensitized? Why make the sensitized area visually identical to the rest?), and3) the board came with at least a sheet of paper describing the location and size of the sensitive area. For bonus points, include a spectral response curve.This board does what it says, but it's going to be a constant battle to remember which part of it is sensitive. If you're using it with high-powered lasers, I suppose dark markings would be a bad idea, but an index mark at one corner at least would be a help (especially with documentation that shows where the sensitive area is relative to the index).EDIT 02-Feb-2025: I've been fiddling with this a bit more, and noticed something interesting: the COLOR of the fluorescence changes with more powerful sources. I have a 940nm flashlight now, and it shows up very clearly as bright green on the sensitized part of this slab. But if I focus the beam down with a lens, the fluorescence becomes brighter AND more yellow/orange. Looking at the spectrum of the fluorescence, there are components in blue, green, and orange/red.I'm guessing that this thing has a blend of phosphors with different fluorescent output under different levels of power, and perhaps different infrared wavelength ranges. The visible color and intensity might be carrying extra information about what's hitting it. I'd love to know more about this, but the manufacturer doesn't seem inclined to post any sensitivity data anywhere. I'd happily give a star or two back if they'd just GIVE US SOME INFORMATION.

Echoing Jeff's review. There's nothing to indicate where the tile is sensitized. Like he did, I believed the whole thing was going to work, but found after close to an hour of messing around with it, that it's just the faintly coated portion. Once you see it, it's easy to find, but there's NOTHING to indicate this and it just arrived in a nondescript box with zero instructions.I was hoping that this would also work with my CO2 laser because that thing is a beast to align (it's a DIY set up that needs work) but I ended up burning the tile by not taking into account the default power on the test setting. My bad. :)