Dual axis electrop-optical scanners using ADP and KDP have been built, but suffered from a low deflection angle, requiring 5-10 prisms of KDP to be placed in series to get a decent swing for a few applications such as a prototype hud for the f14 tomcat. They were basically abandoned in the mid to late 70s as a crystal that was birefringent and cheap and had a sufficient EO figure of merit did not exsist. On a EO deflector, you just apply a suitiable high voltage which changes the index of refraction in the crystal, resulting in a change of deflection angle.
Fast forward to 2009. Keep in mind that what normally appears in Laser Focus World is not usually something you can get your hands on. Once I was in the mailroom at UA and one of the professors came in, scornful to find me reading LFW and flirting with a good looking student assistant (yes, you can flirt with paid staff if you are not their direct supervisor, in fact the university was proud of their high inter staff marriage rate)
What are you doing Steve, he asks? "I'm reading the wishbook of unobtainium that is not in production, that often does not exist, and that we cant afford and will never get our hands on in quanity one..." I answer. Very good he says, "Nowquit flirting with Allie and get back to work.
Well, once, just this once, something showed up in the dreambook we might get ou hands on.
Nippon Telephone and Telegraph found a material with a decent EO figure of merit. Something called Potassium Tantalate Niobate. A PTN crystal, with electrodes on four faces around the light path at 90' Can, according to NTT, deflect a beam at +/- 14' for a applied voltage of +/- 250V. see June 2. 2009 LFW for details.
Since there are no moving parts, this could be damn fast, in fact the limit is how fast you can slew the voltage into a capacitive load. I imagine 100-200 Khz might be possible with care. Its got a slightly nonlinear deflection curve in the low ends, but it could easilybe corrected in software. So start thinking how you get +/- 250V swing into a 10 pf load, as fast as possible.
The protoype in the picture is a cylendar about .5 mm in diameter and maybe 4 mm long.
You need 400 V/mm for peak deflection.
Somebody get a qoute and lets see if we can do a group buy (not holding my breath)
See: http://www.ntt-at.com/products_e/KTN_scanner/index.html
Oh, and unlike previous LFW miracles, this one will be displayed to the public at CLEO.
(only problem might be it could be wavelength sensitive, so what, 4 scan heads for RGBY have proven useful in the past )
I refuse to install quicktime, so somebody tell me if the movie is interesting/..... Steve
And watching BB try to figure out how to make a scanner amp with +/- 300V and 3 db down at 500 khz might be interesting, to say the least. It will certainly allow a quadmod redesign, the QM4000, probably...
Steve