Edit: ScottH beat me to it while I was writing up my post. That second link is a good overview of LC steering methods.
One of the more common ways to steer lasers nonmechanically, at least in optics labs, is with an
AOM. This isn't strictly solid state, as it uses a piezo to create acoustic waves in a transparent crystal material (such as glass). AOMs have pretty much infinite resolution. The downsides are a limited response time and possible distortion when rapidly changing angles, due to the acoustic propagation time in the crystal. They're also relatively expensive for a hobbyist ($1k - $5k+).
There are also a few varieties of beam steering devices using electro-optics - some materials will change their refractive index when an electric field is applied. The basic type is simply an angled interface between the electro-optic material and air. The refracted beam angle will then change very slightly as the refractive index is varied. The angle variation is small, and the devices are usually expensive, which means it would probably not be very useful for you. They're mostly used in optics research.
A somewhat more useful class of electro-optics devices are liquid crystal diffraction gratings. These are pretty much variable diffraction gratings. Liquid crystals have a very high electro-optic response. Using pixels of them at varying refractive indices, you can form arbitrary diffraction gratings, and thus aim your laser. Some brief info is on
page 25 of this presentation. They're fast, and presumably not too expensive, although I haven't been able to find commercial products with a quick search. However, the aiming accuracy is limited by the size and number of available pixels.
My favorite beam steering device is a new type, developed by a local company. Vescent Photonics in Denver has
this device, which has 80 degrees of beam deflection in a very small package, controlled entirely electronically. I was able to see it in person a few years ago at a demonstration at CU, and
it works very well. For an explanation of the details, they have
an informative and detailed paper, and a more recent
SPIE news article. I have no idea how much one of those devices would cost, as it seems it's still built-to-order, but if you have a big budget and small space it might be worth looking in to. If you do get a quote from them, I'd be interested in hearing the cost.
- nickersonm
