What sort of laser scanning? Printers, video displays, terrain mapping,
or what?
I've not attempted to keep au courant on this topic, but I'm assuming
you mean, newer than Handbook of Optical and Laser Scanning, G. B.
Marshall, Ed., Marcel Dekker, 2004.
Thanks. I hadn't noticed that book. I'm sure Gerald's book will have
what I need.
Unfortunately my local library (University of Michigan) does not seem
to have it (surprisingly).
SPIE Proceedings from various Optical Scanning conferences (most recent I
have is from 2002) are probably the best publications, if you're after
recent advanced designs. The only books on scanning are by Gerald Marshall
and Leo Beiser, both of which I recommend to any serious student of optical
scanner design. Of course, scanner system design is more about design
architecture than lens design, and there are many possible options.
I used to run a training course that covered the ground, but it died a few
years ago due to shortage of demand.
--
Ron Gibbs
www.gibbsassociates.co.uk
And also Gottlieb, Ireleand and Ley if you're interested in AO or EO
scanning, deflection. The SPIE journals are a great source for articles
on scanning, as well as SIDS (Society for Information Display). And
if you have a particular scanner in mind, say a polygon, the manufactures
will gladly provide you all sorts of white sheets/app notes specific to
their types of equipment.
d.
Thanks Ron. I'm planning to check out the SPIE papers and will
probably buy Gerald Marshall's book.
Thanks Doug. I'm certainly interested in AO and MEMS scanning. In my
previous search (about 7 years ago) I couldn't find any useful data or
devices on AO. I would expect it posible to steer a laser beam with
very high efficiency. Maybe there are some devices available now.
>Thanks Doug. I'm certainly interested in AO and MEMS scanning. In my
>previous search (about 7 years ago) I couldn't find any useful data or
>devices on AO. I would expect it posible to steer a laser beam with
>very high efficiency. Maybe there are some devices available now.
>
>www.richardfisher.com
You're welcome! I've built a number of mono and full color laser
video projectors back in the late 80's/early 90's that used AO
for the horizontal deflection. The efficiency was not as high as
I would have liked, however the tradeoff's in not having to use
a polygon (non-sync'd time bases) made up for a simpler
design. If you'd like to take a look at a very ugly web page
that I put together of it, here's where to look, and again,
it's not meant to be a pretty website!
http://members.shaw.ca/dulmage/page4.html
Doug
Interesting, thanks. However, I would asume that a suitably driven AO
working in reflection could achieve close to 100% refelctivity if a
suitable standing wave pattern could be achieved. I suppose the
question is how difficult is it to achieve such a pattern and at what
rate could it be scanned.
Well, this is where I start to get in over my head.. The problem with
AO deflectors is that in order to get the suitable amount of spot
resolution, you have to have large bandwidths, yet still be able
to satisfy the Bragg angles which change relative to the input
beam. So, in the case of an AO modulator, it's easy to get
80-90% eff. because of the one fixed frequency. As well,
in the AO deflector, you have to be able to fill the aperture
within the blanking time of your video signal, and in the case
of SD or HD video, as the required time bandwidth requirements
go up, your blanking interval goes down when you actually need
it to be going up. One solution to that is bi-directional scanning,
which is practical now as digital video line and frame stores are
"cheap", back when I was doing this, only analog stores were
available (unless you had Mil money backing you), so bi-directional
was not practical, and for the min. TBW of 400-500 spots for SD
video, you could just squeeze that in during the 6um second hor.
blanking, but the 800 or so needed for HD could not be done
within HD's 3um blanking.. I'm sure there are better devices
available now, NEOS was a good source as well as Crystal
Tech. If I were to be trying to do this now, I'd be looking at
using deformable grating devices (if available), or some other
MEM type device.
Ah, to be young again!!
d.
That's pretty hard. For the usual AO cell, delta-k/k is less than 0.1,
whereas backscatter requires delta-k/k=2. You'd need a 20x higher
acoustic frequency, for a start.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net