Wednesday, June 10, 2009

Pullin' Fibers

This is the Sutter P-2000 Micropipette and optic fiber puller. It uses a CO2 laser to heat up glass and then pull it into very thin strands. I have been working for nearly two weeks to get this machine to make the correct shape on my optic fibers, and I'm so close I can smell the burnt quartz. I calibrated the thing, felt joy when it pulled its first optic fiber, felt despair when it failed. I've gone through a good 8 meters of single-mode optic fiber. That's the cheap kind, but still, its annoying. Until otherwise instructed, my job is to find the one magical configuration of parameters that makes this machine pull an optic fiber into a long, gracefully tapered tip.

The machine gives me control over 5 different parameters:
  • HEAT: Goes from 0-999, and controls how hot the laser gets. The tips tend to get thinner as the heat goes up, but too hot and they start to curl up.
  • FILAMENT: Goes from 0-15, and controls how wide a section of the fiber gets heated up before pulling. According to the manual, you never need to use more than 0 on optic fiber, but I've been experimenting with really high filament values to some good effect.
  • VELOCITY: Goes from 0-255, and in a roundabout way controls how hot the fiber is before the machine gives it the final hard pull.
  • DELAY: Goes from 0-255, and controls how long before or after the laser shuts off the machine should start pulling.
  • PULL: Goes from 0-255, and controls how hard the machine pulls.
I've gotten so close so many times, I don't know if I can go on for much longer without going insane. I'll pull a tip, it'll look perfect and then I'll take it down to the microscope and my grad student mentor tells me "Close, but not quite" really nicely and then she'll show me a good tip under the microscope and I'm completely off. Here's my basic problem:

Guess which one I've been getting?

And what's worse, apparently nobody on the internet has the same problem as me, cause there are no forums or help sites about this machine.

Next article won't be me complaining, don't worry.

Edit: I just found out that Sutter publishes a "cookbook" of programs for pulling micropipettes. 2 problems: I need programs for optical fibers, not micropipettes, and I they haven't published one for my machine, only for the P-97 puller. The P-97 uses an electric filament, not a laser, so it can't melt quartz as well as the laser on the p-2000. Dammit.


Anonymous said...

Hang in there nephew!! Soon you'll be making carbon fiber nano tubes!

Taylor said...

That would be freaking amazing, dude. Carbon nanotubes are like one big molecule, so I bet they would heat evenly, unlike the glass we use now.