Listen, I'm new to this forum. I don't know ANYONE on this board -- at all. So I want to be very careful about calling anyone out. But when a scientist at Lawrence Berkeley National Labs makes a statement about margin of error, I'm going to at least report what he says. Regardless, I have some new readings, which I'll report now in this thread...
No problemo, dude. I'm not trying to call anyone out, and no need to call me out. I just know from my own experience testing literally hundreds of blue laser on optical power meters and from my own experiences answering questions for novices...that 15% number was pulled out of thin air. Like 78% of all statistics, made up on the spot. :beer:
Nothing wrong with reporting it, you're doing your job, and a fine job at that. I appreciate your effort, honestly, and I feel that you're doing a great service. And I'm sure that scientist feels like it was a good guess, but it was just that, a guess. And nothing wrong with that, either, to be honest.
But in defense of my position, your current results seem to indicate he was incorrect. No matter which way you slice it, it would seem your first measurement has an error of at least 25% if your Lasercheck is to be believed. Since your Lasercheck is likely actually calibrated at 445nm, then I'm much more inclined to believe it's closer than a detector calibrated for IR, not to mention all the spec that have to be taken into account when switching from an unknown IR light source to a collimated blue CW light source. Honestly, his calibration could've been fine and instead the detector was locally saturating because of the collimated blue light. Who knows?
Honestly, measuring light in the blue region is a very new science topic compared to doing it in IR. They've been measuring IR lasers for decades now, and blue laser diodes for just a few years. IR lasers are many times more common, and there are hundreds more people experienced with them, and those people just haven't measured blue lasers before. It's a struggle, definitely. I've been trying to find and buy a photodiode with specific specs that is tracibly calibrated for the UV-blue region for measuring laser diode power output for over 6 months now, and it's simply very difficult to find such things, they're just not as common. It's not your fault, it's not his, but "15% error" in that case is hokum. :yh:
