Sam’s Laser FAQ – Preface, Introduction

With talk about the blu-ray laser having potentially dangerous attributes if the beam got out, I decided to find the definitive FAQ on lasers. Here it is. Lots of good information. Still digging around for details on blu-ray.

Barcode Scanner Safety
The light source in a supermarket or other common barcode UPC (Universal Product Code) scanner is either a .5 to 2 mW HeNe laser (632.8 nm orange-red) or a 1 to 5 mW diode laser (most often around 670 nm, red). So, while the beam may appear bright, as long as it is scanning at all, there is no risk to vision or anything else. (The average power into your eyeball is probably less than 10 microwatts.) And, as with laser pointers, you would really have to go out of your way for there to be any possibility of damage even if the beam was stationary due to a failure of the scanner.

You can tell the difference between the types of scanners by the color of the light. The beam of the diode laser based scanners will appear a much deeper red than that of a HeNe laser based unit. (If you are into lasers, this is one of the ‘rites of passage’ so to speak – to check out the local groceries and supermarkets!) Of course, the other way to tell is that if your store installed checkout scanners when the UPC was new technology, and hasn’t upgraded since, they are almost certainly based on HeNe lasers. (Barcode scanners of all types, shapes, and sizes are often available from surplus outfits as well as on-line auctions like eBay. At the right price, they represent an excellent source of laser and optics related parts – even if you don’t want to use the unit for their intended purpose.)