
[bodiby] was first to send in this New Scientist article about converting a DVD drive into a lab scanner. I did some digging and came up with the details. Here’s the paper describing the process and results. Here’s a basic schematic and description of the mod. A set of samples is placed onto a CDR. A photo sensor is used to locate the samples on the CD, while the laser is fired through each sample. A planar photodiode is used to measure the attenuation of the laser as it’s transmitted through each sample. Sadly, I couldn’t find any details on the custom control electronics.
Laser Hacks653 Articles
Remote Laser Security Camera Defeat

[John] sent in this cell phone activated rifle scope laser security camera blinder. The phone plays a tone when it receives a SMS message. The sound activates an audio controlled relay. (Not elegant, but it works) which powers a laser that’s been mounted to a rifle scope. The scope is used to align the laser with the target lens – on activation it’s supposed to blind the camera. Looks like a fun hack, even if the uses are a bit nefarious. (He left out a little detail that’ll make or break the project to keep things on the level, but it’s not that hard to figure out.)
Switchmode Power Supply Hacking (power Your Laser)

[Mike] wanted a better power supply for his argon laser, so he modded some switchmode power supplies. With a few tweaks, he had a few adjustable voltage outputs and a nice solid supply of electrons for his laser projects. If you need a lab quality adjustable power supply for your projects, this is a nice way to get it on the cheap. (He’s in the UK, but the same ideas should apply to us models.
Acoustically Generated Holograms

I found this on [hackedgadgets] and checked out the paper describing the project. I’m not sure if it will generate any truly usable graphics any time soon, but the technology is pretty interesting. It combines six video channels and uses acoustic frequencies and tiny but simple looking transducers to vibrate the crystal that channels a laser to generate the hologram. (If I read that paper correctly) Surprisingly, a single nvidia chip generates all six channels for the system. Annoyingly, there’s a lack of info on MITs site, but there’s a nice group of images under the multimedia link of this article.
Interactive Laser Drawing (graffiti)

This hack was linked a bit back in February, but it just didn’t get a decent write up. They used this 5000 lumen projector, a zoom lens video camera and a 60mw green laser pointer to generate interactive graffiti on nearby buildings. Most of the link love focused on the show-off video. I’m surprised that nobody mentioned the most obvious use: a laser pointer reactive white board. I could have loads of fun with this and my laptop during presentations. Thanks to [Brishen] for reminding me of this one.
Laser Power Meter Sensor

I signed the papers on my first house today! In celebration, I started looking for some home hardware hacks, but stumbled across this old (2003) laser power meter sensor. If you like to scare off the power guys, this is the way to go. [jake] used a laser pointer, probably a PIC and some sort of photo sensor to count the revolutions of his meter.
TinyProjector: Mini POV Laser Projector

I found [Stefan]’s work through his older, but interesting TinyProjector project. He opted to use multiple diodes in various configurations with rotating mirrors to create images. He’s built quite a few interesting projects over the years. The WeatherTank is pretty sweet.