Re: WARNING NOTICE !

"Arne Chr. Jorgensen" wrote:

> From: "Arne Chr. Jorgensen" <instel@...>
>
> Hi Elliot,
>
> The stuff you wrote was great, let us know where to find your
> homepage when you got something. I don't have time to say much
> right now, I just would like to give a warning.
>
> It would be very tempting to look at into that microscope, - but I
> feel very uneasy at the thought of focusing into a laser beam. Even
> 1mW has shown eye dammages. You may focus it on a sheet of paper,
> and that may have been what you ment.

I built a laser photoplotter, and had the same problem. The film
itself is a very good absorber of red light, so I used paper with the
right thickness to place the top of the paper at about the same height as the
sensitive layer of the film. For serious beam development, I use a
pulse generator that can deliver 1000 short pulses per second.
For a quick check, I can run the laser with a series resistor, but
that affects the characteristics of the beam emitted from the laser
diode. With these arrangements, the emitted power is low enough
to be observed with a microscope. With the laser running near
5 mW CW, you definitely can't look at it closely, with or without
magnification.

Jon