Re: ATM Fiber light source - a burning issue

[Aplanatic@aol.com]

P. C. wrote:

> If anyone on the list so desires, he/she should feel free to send me a 
>  couple of fibers with the ends already melted into a perfect 1mm diameter 
>  ball.   Taking a leaf from the guys at the PBS Car Talk program,  I'd also 
>  like to have the  fibers wrapped carefully for shipment, preferably in two 
>  twenty-dollar and one ten-dollar bills.  :-) smile.

My lovely wife has a complete hot glass (and stained glass) 
"laboratory" in our garage.  Since she's been taking up all that 
room and interfering with my telescope making space for 15 
years, I feel no qualms about using her equipment for this fine 
experiment. <grin>  So, I'd be happy to try pulling some fiber 
from her soda-lime glass rod supplies.

What diameter would you like the fiber to be?  May I suggest 
about 0.2 mm?  How long do you need the fiber to be?  It will 
be tough to make it much longer than 1.5 meters.  One end is 
formed into a ball.  What do you want the other end to look like?  
May I suggest that both ends are spherical balls to facilitate 
coupling the fiber to a laser?

I am currently testing a new Schmidt camera plate, so I have a 
strong motive to make this work.  Right now I'm using a ball bearing 
at the focus of the Schmidt camera to make a point source, but this 
fiber optic idea has its merits.  

Has anyone calculated the effective size of the source from a 
fiber with a 1 mm diameter ball lens?  What is the spherical 
aberration of this source?  Negligible, I hope!

Dave Rowe.