The laser arrived in the mail yesterday! Exciting!
It is a 110mW 657nm red laser module with TTL blanking.
The system below is a Pangolin Pro on Cambridge CT6800HPs
with the CatAMP IV accelerated amplifiers. Some are also taken
with a proprietary 16-bit frame-buffer based laser control system.
Most of the pictures below are scanning at 40kpps at about
20 degrees. These scanheads are tuned to scan the ILDA 12k
pattern correctly at 30kpps at 45 degrees. I prefer 35k+pps
because designers who design for 30k usually push the
boundary of what's acceptable flicker and what's terribly annoying.
Present was also a small amount of haze from a hazer. I prefer
hazers to foggers because a moderate sized fogger will
completely obscure even a 5W argon beam!
I had an initial problem in that new laser wouldn't completely
extinguish the beam because of the length of the cable
to the laser head, the original 5V dropped to 4.6V! This normally
isn't a problem since most offboard devices are CMOS level
triggered. Empirical testing showed the laser's blanking working at 5V.
So I had a burst of ghetto inspiration... Now what I really needed
was a 74LS244 (octal buffer) to boost the voltage locally to 5V,
but all I had was a bunch of 7404's (hex inverter) which
(as it is aptly named) inverts the signal (5V->0V and 0V->5V)
so I simply tied two inverters together to undo the inversion,
bringing me back to usable TTL levels. The photos below are
before I added this corrective circuit.
The TTL level fix (Complete with capacitor)
The ghetto bottom.
With enough heatshrink, you can't see any ghetto!
So this is the new laser, jury-rigged on top of my scanheads.
This scanhead normally takes a SMA fibre-fed laser, but aligning
SMA fibre-feeds is a pain and max did such a good job with
collimating the optics, that I felt bad about realigning it to
focus on the fibre optics.
It's a nice bright red!
These pictures don't do it nearly enough justice.
A dino (from Anthro's pack 6)
A fireman (from Pangolin's 40hr week show)
The calibration grid. It's actually square, even though it
doesn't look like it. The camera was at an angle.
Another shot of it in the dark...
You can also download a short 4MB clip of it running a beamshow.
http://12.149.165.76/howdy/newred_beamsho.AVI