New user, laser score!

[mrehorst]

The boss was cleaning out a closet at work and was getting ready to pitch a dental curing light (LaserMed Accucure 3000) into the trash until I rescued it. When I got it home and looked at it I discovered it is an Argon laser. It has a LaserPhysics Reliant 300b tube. In spite of sitting in a closet, unused for who knows how many years, I powered it up and it lit right up. My initial test with the built in power meter was reading only about 80 mW out, but I've let it run for a while in the last couple weeks and power is now up to about 120 mW.

I haven't been able to locate any data on the tube (or a manual for the curing light that contains it), though I did find a web site that has a sample spectral output from it- there were a few blue and a few green lines and that's it. Does anyone know where I can find some data? The built-in hour meter says it has 2800 hours on it. Is that young, middle age, or old? Since it was used in a dental curing light, it may not have been designed for continuous operation. What is a safe duty cycle for it?

The normal output is via a fiberoptic handpiece, and there a small lens to spread the beam at the output of the laser to light up the whole fiber bundle. I can remove the lens and then I get a nice narrow beam out of it.

Now I have to decide what to do with it... I'm open to suggestions...

 

[diachi]

Now I have to decide what to do with it... I'm open to suggestions...

Admire the pretty beam?

If you put a CD (or DVD) in front of the beam it'll act as a diffraction grating and split the lines out, then you can count them!

As far as the hours on it, that's sort of middle-aged. Really depends how hard it was run. Those are good for 100% duty cycle AFAIK, could be wrong. There's a couple other people here with those that'd be able to tell you.

 

[LSRFAQ]

It has "kill Green" mirrors on the tube. You get blue, violet, and a bit of green at higher currents if the tube is healthy. So dont expect the usual 300-350 mW from a fresh Reliant from this puppy.. After all, it was for curing blue sensitive photopolymers.. Green light inhibited the curing process by creating useless heat.

The most I've ever seen at max current is ~200-225 from those... I had three of them at one time.

I used to have the manual, but no more.. There was no schematic.. Just some lifetime data vs Current settings.

Let it run its cooldown cycle if so equipped. That does wonders for keeping the lifetime up.

They drove those tubes hard. Be happy at 80-100 mW and it will serve you a long time.

Your looking for "Premier Dental" or "Premier laser" in Salt Lake City for the patents and laser data. It was remarketed under a few different brands.

That is pre-menopausal.. Not quite old, but not middle aged either. Curing tubes were operated at settings that emphasized "We're Cooking Now", mainly because the early resins tasted like having a toxic waste spill in your mouth, so the Dentist was always in a hurry to get done. "Mor Power" didn't always mean faster cure either, but that is the perception. Man that stuff tasted bad if it leaked out of the dental dam, placed around the tooth. I need to go eat lunch now,, because I have a "burning" memory of what that flavor tasted like..


Steve

 

[mrehorst]

Thanks for the info! I ran it through a diffraction grating last night and saw 6 lines, 3 distinctly blue and three that were more green than blue.

I noticed that with the beam off (foot pedal not pressed), I can see some blue light leaking from the back mirror on the tube- is the beam on all the time and they just open a shutter when the foot pedal is pressed? There is some sort of electro mechanical device at the output end of the tube... maybe a shutter?

 

[paul1598419]

I remember that early composite too, though I never got it into my mouth.

 

[LSRFAQ]

You have incoherent plasma light from the arc. If the tube is still decent you might get weak lasing all the way down to idle. Medical devices, by law, have a mechanical shutter or two or three shutters depending on the device and its function. So yes, there is a tiny solenoid shutter in there and they keep the plasma lit at all times. It is easy to remove the shutter if you tear apart the fiber mount. The fiber is a really efficient bundle of fibers, not one single fiber. The optic was really designed to reduce the powerful 514.5 nm green line.

Steve

 

[mrehorst]

I'll look at taking the shutter out and see if the beam is on all the time. When I step on the foot pedal the cooling fan speeds up, so I guess the beam is off until the pedal switches it on and opens the shutter.

 

[paul1598419]

My understanding is the beam is present at all times, but is at full current when the pedal is depressed. That is why the fan speeds up.