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Ann Arbor Area Business Monthly
Small Business and the Internet

Blue Lasers From Hell

August 2010

By Mike Gould

This article is based on a (mercifully short) talk I gave at a GO-Tech meeting recently. Go-Tech is a monthly meeting of makers, techies and machinists that assembles in a communal machine shop to show off projects and meet & greet. Sort of a C of C for the mechanically creative set. URL below. The following is a rant and cautionary tale, and while I generally don't believe in spreading mass hysteria, sometimes a little mass hysteria is called for.

Cats Bananas
Consider your basic laser cat-toy. You shine it on the carpet and Fluffy freaks out, chasing it around the room, until she wises up and realizes that that !%$#? red dot is uncatchable. Our cat Daisy has gotten pretty blasé about this by now.

This contains a way-tiny laser that has a power measurement of around 5mW (5 milli-watts: 5 thousandths of a Watt) and is considered to be quite harmless. The heart of the pointer is a laser diode, sort of like an LED on steroids - instead of the light emanating in all directions as with an ordinary light bulb or LED, the photons are directed in a single beam, causing the cat-entrancing red dot.

The lasers we use in our laser lightshow (Illuminatus) are in the 10 to 200mW range, a bit more hazardous, but safe in the hands of trained professionals, which we are. We would like to be using higher-power lasers, but these require special handling and are very expensive. Or, they were up until early June, 2010.

Don't Lase Me, Bro
Suddenly, without any warning, blue laser diodes started appearing on eBay for around $75. And there is a company in China, which I will call EvilLasers, selling a hand-held 1 Watt (1,000mW = 1W) blue pointer for $200. Which means that any idiot with $200 can have a laser light saber that will burn flesh, cause instant blindness from hundreds of yards away, and is completely unregulated. Oh, and you can take the raw diodes and goose them up to 2W if you know what you are doing.

This is a personal directed beam weapon. A Buck Rogers ray gun. Insanely dangerous. It is not going to cut you in two, but it will scar your skin and cause instant blindness if you even bounce it off of a reflective surface into your eye.

I belong to an online forum called PhotonLexicon (PL), and also monitor several other laser-related forums, such as the LaserPointerForum (LPF). PL is for serious enthusiasts who largely build their own lightshow gear, and LPF consists mostly of kids wanting high-power pointers so they can pop balloons and burn electrical tape. The pros at PL are mostly appalled at this 1W portable death ray, and the laser kiddies at LPF can't wait to get their hands on one.

Projectors Unleashed
So where the heck are these laser diodes coming from? Therein lies a tale of very twisted technology. It seems there is a maker of video projectors, which I will call Crassio (the names of the parties involved are being disguised because I Really Don't Want Anyone Following Up On This And Buying Something Insanely Dangerous).

Crassio recently came out with a new line of projectors that use conventional high-power LEDs to power the red and green aspects of their lighting, but picked an array of 24 laser diodes to provide the blueness needed for an RGB (red-green-blue) display. Some twisted genius, out there, somewhere on the Internet, read the technical description of the projector, and said "OMG, WTF, native blue lasers! Dirt Cheap! I can make a fortune buying up $800 projectors, tearing the diodes out of them, and selling them for $75 a pop on eBay!" And so he did. And so did a lot of other people, driving the price down to around $45 if you know where to look.

There is now a cottage industry of people buying these projectors by the palette-load, stripping out the blue mojo, and selling the diodes on eBay. So why don't they just buy the diodes from the manufacturer? Because no one can find them for sale anywhere. The theory is that Crassio signed an exclusive agreement, buying all the output of that one diode factory in Shenzhen, or wherever. As a result, there are now, in piles throughout the planet, dusty heaps of perfectly good RG projectors.

Why is only one factory producing these? Because this is a major technological breakthrough. In the past, red laser diodes = very cheap, green laser diodes = cheap, blue laser diodes = EXPENSIVE. As an example, the lasers we use in our lightshow average around $80. We have two blue lasers, and paid around $450 for them, getting a rare deal on eBay as part of a loss-leader sale for lasers that usually cost around $1500. Note that these are raw lasers: we buy them and hand-build them into lightshow devices.

Lase Me The Money
Up until now, the blue lasers were created by shining a cheap infra-red (IR) laser through a very expensive crystal that would multiply the frequency of the light into the blue range. This is called a Diode-Pumped Solid State (DPSS) laser - the new diodes are "native" in that they output blue directly with out being driven by an IR laser. That is the technical breakthrough: no more expensive crystals.

And no, this isn't the same blue that is used in Blu-Ray disk players: that blue is really a violet, almost into the ultra-violet range which makes them very difficult for the human eye to see. And yes, there are people buying up obsolete and used HD-Video disk burners and harvesting the lasers from these.

Cause for alarm? You betcha. As of this writing, EvilLasers have yet to actually ship anything, but they probably will by the time you read this. George Lucas is suing them, saying the product looks too much like a light saber.

The laser lightshow community is very concerned that someone will wave around one of these at a party or rave and blind a bunch of people. But they also worry that the resulting outcry will cause legal regulation so tight that it will legislate laser shows out of existence.

So if you see an intense beam of blue light coming from the dance floor, duck and cover, and head for the exit.

GO-Tech: http://tech.groups.yahoo.com/group/notbago/

PhotonLexicon: http://www.photonlexicon.com/forums/forum.php

Mike Gould, was a mouse wrangler for the U of M, runs the MondoDyne Web Works/Macintosh Training/Digital Photography mega-mall, is a member of the FacTotem constellation, builds lasers into lunchboxen, performs with the Illuminatus Lightshow, and welcomes comments addressed to mgould@mondodyne.com.