Cecil Moore wrote:
Gene Fuller wrote:
Does Hecht really say that more power goes into the glass than enters
the 1/4WL film? Can we somehow bottle this free energy and save the
world?

Gene, here's a complete fixed font irradiance diagram of
the air to thin-film interface including all components.
Reflectance = 0.01, Transmittance = 0.99

Forward irradiance component

Ifor=1W --|
|-- I1=0.99W
I3=0.01W--|

air | thin-film

Reflected irradiance component

|-- Iref=0.0101W
I4=0.01W--|
|-- I2=0.0001W

I1 + I2 + 2*SQRT(I1*I2) = 1.0101W = Ifor in the thin-film
This is "total constructive interference" per Hecht.

I3 + I4 - 2*SQRT(I3*I4) = 0W = Iref in the air
This is "total destructive interference" per Hecht.

Those are the irradiance equations from "Optics", by Hecht.
As Hecht asserts, the destructive interference equals the
constructive interference and the reflections toward the
source are canceled.


Cecil,

Don't bother. I understand the physics quite well, thank you. It is your
message that causes grief. On the other hand, I don't really care to
try to educate you any further, so the grief is quite small.

73,
Gene
W4SZ

Gene Fuller wrote:
Don't bother. I understand the physics quite well, thank you.

So, is anything technically wrong with what I posted?
It is all copied out of various parts of "Optics", by
Hecht.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:

Don't bother. I understand the physics quite well, thank you.


So, is anything technically wrong with what I posted?
It is all copied out of various parts of "Optics", by
Hecht.

From what page in "Optics" by Hecht is the 1 watt laser problem and
analysis copied?

73, Jim AC6XG

Jim Kelley wrote:
From what page in "Optics" by Hecht is the 1 watt laser problem and
analysis copied?

The 1 watt laser mental exercise is my idea. Everything
else is directly from "Optics", by Hecht.

A 1 watt ideal laser was chosen for its single frequency
and coherent characteristics to avoid any more "brighter
than the surface of the sun" postings.

Why are you afraid to discuss a 1 watt laser?
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
Don't bother. I understand the physics quite well, thank you.

So, is anything technically wrong with what I posted?
It is all copied out of various parts of "Optics", by
Hecht.

Cecil,

Yes, there was something technically wrong. The message I responded to
had a glaring violation of conservation of energy. Your follow-up
corrected the problem.

73,
Gene
W4SZ

Gene Fuller wrote:
Yes, there was something technically wrong. The message I responded to
had a glaring violation of conservation of energy. Your follow-up
corrected the problem.

Gene, as you know, there is no such thing as a violation of
conservation of energy. But the reflectance at the thin-film
surface is 0.01 and a reflection is unavoidable. So how does
the reflected 0.01 watts/unit-area of irradiance keep from
violating the conservation of energy principle? Where does
that energy go? My follow-up answered those questions. Two
rearward pointing power flow vectors are associated with
wave cancellation of the EM fields. That's destructive
interference resulting in constructive interference in the
opposite direction.
--
73, Cecil http://www.w5dxp.com