Jim Kelley wrote:
Cecil Moore wrote:
I am preparing a picture that hopefully will be worth
a thousands words.

There are far too few such pictures in the world in my opinion.

I'll try to have it posted to my
web page by tomorrow.

Thanks. I am interested in seeing it.

OK, the graphic is at http://www.w5dxp.com/thinfilm.gif
It is the beginning of the transient state. The drawing
is offset for illustration purposes but assume the laser
beam and all the reflections are collinear.

There are times associated with events:
t0 is when the laser is turned on
t1 is when the laser beam first reaches the thinfilm
and the external reflection takes place
t3 is when the first internal reflection reaches the
thinfilm

Questions: What is the power reflected toward the source
between t3 and t5? What happened to the 0.01 watt of
external reflection? How did the reflected power decrease
unless there was partial wave cancellation? What is the
steady-state reflected power toward the source?
--
73, Cecil http://www.w5dxp.com