Reflected Energy
 

Here's an interesting website:

http://micro.magnet.fsu.edu/primer/j...einteractions/

Destructive and constructive interference can be explored
using a javascript application. What is asserted at the
bottom of the page is particularly interesting:

"In addition, when two waves of equal amplitude and wavelength
that are 180-degrees (half a wavelength) out of phase with each
other meet, they are not actually annihilated, as suggested in
Figure 1. All of the photon energy present in these waves must
somehow be recovered or redistributed in a new direction, according
to the law of energy conservation (photons are not capable of self-
annihilation). Instead, upon meeting, the photons are redistributed
to regions that permit constructive interference, so the effect should
be considered as a redistribution of light waves and photon energy
rather than the spontaneous construction or destruction of light.
Therefore, simple diagrams, such as the one illustrated in Figure 1,
should only be considered as tools that assist with the calculation of
light energy traveling *in a specific direction*." i.e. if Figure 1
didn't ignore reflections, there would be wave(s) traveling off in
some other direction(s).

Translating this to the match point in a transmission line with
reflections: Destructive interference between two reflected waves
cause the elimination of reflections toward the source in a matched
system. "All of the photon energy present in these (canceled) waves
must somehow be recovered or redistributed in a new direction, ..."

There's only one other direction in a transmission line and that's
back toward the load. When the reflected energy is re-reflected
(redistributed) at a match point, it is simply following the existing
laws of EM physics.
--
73, Cecil, W5DXP

On Thu, 18 Nov 2004 12:49:36 -0600, Cecil Moore
wrote:
"All of the photon energy present in these (canceled) waves
must somehow be recovered or redistributed in a new direction, ..."
Was and has been Orthogonal to the direction of propagation - nothing
has changed.
There's only one other direction in a transmission line and that's
back toward the load.
This does not follow from the other.

Richard Clark wrote:

On Thu, 18 Nov 2004 12:49:36 -0600, Cecil Moore
wrote:

"All of the photon energy present in these (canceled) waves
must somehow be recovered or redistributed in a new direction, ..."

Was and has been Orthogonal to the direction of propagation - nothing
has changed.

There's only one other direction in a transmission line and that's
back toward the load.

This does not follow from the other.

Moreover, the point being missed by the original correspondent (one
which is obvious from this and other descriptions of the phenomena), is
that no _energy_ is transferred in the direction of totally destructive
interfering waves - a point which I have made repeatedly on this
newsgroup, and which he has steadfastly refused to accept. The
observation that the energy in question must go elsewhere remains obvious.

73, Jim AC6XG

Richard Clark wrote:

Cecil Moore wrote:
"All of the photon energy present in these (canceled) waves
must somehow be recovered or redistributed in a new direction, ..."

Was and has been Orthogonal to the direction of propagation - nothing
has changed.

The Melles-Groit web page says: "In the absence of absorption or scatter,
the principle of conservation of energy indicates all "lost" reflected
intensity will appear as enhanced intensity in the transmitted beam."

This is in regards to a thin-film anti-glare coating. If a laser beam
is perpendicular to the plane of the thin-film, the reflected beam
and the transmitted beam will lie in a STRAIGHT LINE. Where did you
get the idea that it has to be "orthogonal to the direction of
propagation"?

There's only one other direction in a transmission line and that's
back toward the load.

This does not follow from the other.

Sure it does. There are only two directions possible in a transmission
line and if energy traveling toward the source is "redistributed in a
new direction", there exists only one other direction available, i.e.
toward the load.
--
73, Cecil, W5DXP

On Thu, 18 Nov 2004 14:20:48 -0600, Cecil Moore
wrote:
Where did you get the idea that it has to be "orthogonal to the direction of propagation"?
A commonplace of Optical Engineering as taught, practiced and observed

Jim Kelley wrote:
Moreover, the point being missed by the original correspondent (one
which is obvious from this and other descriptions of the phenomena), is
that no _energy_ is transferred in the direction of totally destructive
interfering waves - a point which I have made repeatedly on this
newsgroup, and which he has steadfastly refused to accept.

You know that's a false statement, one of many you have made about
my postings.

Of course, no energy is transferred past the match point in the
direction of totally destructive interfering waves. DUUUHHHHHH,
THAT'S WHY THE REFLECTED POWER METER READS ZERO ON THE SOURCE
SIDE OF THE MATCH POINT, DUUUHHHHHH. And that's why the reflected
energy traveling toward the source on the load side of the match
point gets redistributed in the only other available direction,
i.e. re-reflected back toward the load.

What I said was: For two reflected waves to cancel, they must
first exist even if for only an infinitesimally small amount of
time. Since you disagree with that, it means the reflected waves
never existed. And if, as you say, they never existed, how could
they possibly cancel? You seem to have invented a new phenomena -
two waves canceling without the waves ever existing.
--
73, Cecil, W5DXP

Richard Clark wrote:

Cecil Moore wrote:
Where did you get the idea that it has to be "orthogonal to the direction of propagation"?

A commonplace of Optical Engineering as taught, practiced and observed

| |
Laser--------| thin-film | glass ...
| |

Where are your orthogonal beams of light?
--
73, Cecil, W5DXP

On Thu, 18 Nov 2004 15:32:53 -0600, Cecil Moore
wrote:
Where are your orthogonal beams of light?
Where do you see the words "beams" in
"All of the photon energy present in these (canceled) waves
must somehow be recovered or redistributed in a new direction, ..."
or are you impeaching your own evidence?

Richard Clark wrote:
Cecil Moore wrote:
Where are your orthogonal beams of light?

Where do you see the words "beams" in

"All of the photon energy present in these (canceled) waves
must somehow be recovered or redistributed in a new direction, ..."

or are you impeaching your own evidence?

I believe the proper response is "non sequitur", i.e.
your response makes no sense at all. If your orthogonal
responses are not "beams of photons", pray tell, exactly
what are they?
--
73, Cecil, W5DXP

On Thu, 18 Nov 2004 17:15:08 -0600, Cecil Moore
wrote:
pray tell, exactly what are they?
Perhaps you should brush up on the first principles of Optics