Date: Wed, 30 Oct 2002 12:46:55 -0500

Author: "Jason St. John"

Subject: Re: Dichroic Microwave Polarization



I'm confused by the way you use the term 'dichroic'. Do you mean that you
have microwave transmitter emitting more than one wavelength, and a pair
of BBQ grills which filter that spectrum selectively (in transmission or
even in reflection)? Or does dichroic not mean "having two (or more)
colors" in the term 'dichroic polaroid filter'?
Jason St. John 617.353.2634
Boston University Physics Lecture Demonstrations

On 2002-10-30.10:59 sent:


With regards to dichroic polarization, I am at a total loss to
explain how one would be able to either perform or measure such with
the meager apparatus this office provides to the classroom.

What we basically provide, is a microwave transmitter, two barbeque
grills and a receiver horn connect to an audio amplifier. One can
attenuate the quantity of radiation that reaches the receiver horn by
placing the grill at a 45 degree angle between the two horns.
However, I' m not prepared to call this dichroic polaroid filtering.

My opinion is the that the demo as it is currently performed shows
absorption of the E-field by the metal bars of the grill acting as
dipole antennae, which then is radiated out as heat.


All the Best,

Andrew Yue
- -
Physics Lecture Demonstration Office
Office Hours 8AM to 4PM Mon - Fri
Phone (512)471-5411