On Sep 11, 2:55*pm, Richard Clark wrote:
On Thu, 11 Sep 2008 09:38:46 -0700 (PDT), Art Unwin



wrote:
On Sep 11, 10:37*am, Richard Clark wrote:
On Thu, 11 Sep 2008 06:18:14 -0700 (PDT), Art Unwin
wrote:
If I have a flash light that is focussed does this wavelength aproach
still apply?

The reflector (or magnifier lens, take your pick) is on order of at
least 1 centimeter. *The light wavelength is on order of 500
nanometers.

Ratio = 20,000:1

Beam is generally no narrower than 15 degrees. *At a distance of, say,
6 feet, that beam would cover a diameter of 18 inches. *Nothing like a
Lazer (sic) if that is the goal.
I see no basis for the inclusion of wavelengths when one is not using
a straight radiator

Read your own question. *There is no such thing as a "straight
radiator" of light. *There is everything to do with wavelength or you
could never see light.

73's
Richard Clark, KB7QHC

If you say so and are comfortable with that then stick with it !
My thoughts are with the reflector and it's design

On Thu, 11 Sep 2008 13:21:15 -0700 (PDT), Art Unwin
wrote:

Read your own question. *There is no such thing as a "straight
radiator" of light. *There is everything to do with wavelength or you
could never see light.

If you say so and are comfortable with that then stick with it !
My thoughts are with the reflector and it's design

Let's just confine this to light, wavelength, and reflection. Try
looking at yourself in a full wavelength mirror. It would be
somewhere between 450 and 650 nanometers wide or roughly the size of a
virus or bacteria.

Practicality demands a reflector vastly larger than that for simple
and ordinary usage. I seriously doubt you have seen a mirror smaller
than 20,000 times that size. Even so you wouldn't be able to see
anything more than your eye in it - or with advanced optics, your
face.

Would that larger mirror have any more gain that one that was one
thousandth its size? No, not to speak of in any practical sense.
Texas Instruments invented the DMD for today's projection TV systems
that use mirrors that small.... for one pixel of light. Their DMD
chip has a vast array of at least 1000000 of these mirrors. Most of
the light in the system is lost. Efficiency is thus very poor, but
that is not an economic issue.

In a way, it most conforms to the same issues of poor efficiency in a
small radiator: most of the RF power is wasted before it gets into the
sky. Unfortunately, for most practicing Hams, this is a very serious
economic issue.

Here's a practical challenge for the reader: Take a Christmas tree
bulb of 7.5W. Employing every trick of the trade of optics, how much
of that available power can you get into a 100 micron fiber optic?

73's
Richard Clark, KB7QHC