(License Plate of a White VW Rabbit)

OK, I am a little embarrassed to be more than fashionably late to the blogohedron party, but this is the 50th anniversary of the laser, and the APS (and some partners) have launched the laserfest website, with lots of stimulating, coherent goodness. Also, Jennifer gives us the festival of lasers

Jennifer points out that

There are several different types of lasers. Solid-state lasers use crystals whose atoms are arranged in a solid matrix, such as ruby. CO2 lasers emit energy in the far-infrared and microwave regions of the spectrum. This type produces intense heat, and is capable of melting through objects. Dr. Evil coveted such a laser when he demanded “sharks with frickin’ laser beams” on their heads to torture Austin Powers to death – only to be foiled because sharks are an endangered species. Imagine his disappointment if, in addition to having to make do with cranky mutated sea bass, they were equipped not with CO2 lasers, but with conventional diode (semiconductor) lasers. These are the type used in pocket laser pointers and CD and DVD players. They are not even remotely lethal.

But beware. Semiconductors aren’t all wimpy — you can get fairly high power diode lasers, and amplifiers that will put out a respectable amount of power. Generally these amplifiers are tapered so the the output beam is larger than the input, so you don’t blow the device up, and the output facet is antireflection coated so that the gain is single-pass (it won’t lase very well on its own). A Watt (or several) of laser power may not be lethal, but it can burn you nicely if it’s focused down, and I have empirical data to back that up. It can also do retinal damage, and that can ruin your whole day.

Remember, kids: Do Not Look Into Laser with Remaining Eye