A 'blast from the past' just for fun

[JasonB]

Hi All,
Great to see these oldies that have been posted!

Well I got a 20kpps scanner from midwest-laser (went for 20K to have more budget for lasers and will regret not getting 30K or higher but you gotta start somewhere). The scanners performed as advertised - check out the quacking duck generated from the old Laser FX software that runs under an amiga emulator. The vendor set the scanners up for a 1 Volt P-P signal so they can run off the sound card. Ok, old news, only 20 years behind, right?
So as to not miss any history of this hobby I breadboarded a popelscan interface with RGB TTL. Set the op-amps offset (correction amp) for 0 VDC and gain to 1 V p-p signal to be compatible with the scanner amps for now... Success! OK, only ten years or so behind now and not ILDA standard but its working.
Got pretty excited with the old school LPT driven DAC so next I built and wired a constant current source driver (c4r0's design) to one of the TTL modulated outputs to try blanking. Well I took a 'shortcut' and tried modulating a 200 mW blue laser pointer (with the pointer's electronics still intact) with c4r0's driver just to see if it would work. The blanking did "work", however large trails existed 'after' the laser turned off. I read about 'jelly-beaning' and figured that the LD must be driven directly for speed, is this correct? Will eliminating the pointer's driver allow the pointer to turn on/off quick enough?
SO ... I could not find out because when I went to take apart the pointer so we could drive the LD directly look what we find: check out the picture.... FAILED! The expoxy prevents access to the LD.. now what should I do? Save up for lab quality laser modules? Or buy a sled and harvest a couple LDs and pick up some flexmod drivers or build an analog DAC [for USB soundcard solution] as attached? I'll need an host such as an aixiz module and collaminating lens if go down the sled harvest road, correct? Already purchased a 100mW red, 200 mW blue,and green pointers.... It is not an option to turn them on/off fast enough for blanking is it? Should have gone straight to 0-like, right?
Thanks for reading; anything you guys can share will be really appreciated.
Does this seem like an OK deal for a laser diode module? http://www.midwest-laser.com/html/la...e_modules.html - ~$80 for 60 mW. If not can you please recommend a decent vendor for a reasonable laser module for a beginner to get hooked...

P.S. USB DAC arrived and correction amp kit is on the way, will make it to the 21st century eventually

Thanks for reading .... Boy oh boy I smell a money pit here ! But what fun !

Jason

[kecked]

directly modulate the diodes with a flexmod p3 driver. You can drive all the diodes this way. In fact you can drive the green dpss driver diode this way as well. Just be carefull increasing the current on the pump diode a little at a time until it starts to lase and them measure the rated output.

What you see it the big honking cap in the driver circuits that is causing the lag. Those drivers are meant to just turn on and off slowly.

If you can't get the p3 drivers, try the die4laser drivers.

I assume you know how to use dichroic mirrors to combine the lasers into a single beam.
You should be able to fit the entire unit sans scanners in a pack about the size of a pop can.