Date: Mon Oct 26 12:32:00 2009 ** **Back to Contents ** ------------------------------------------------------------------------ **

Author: Zani, Gerald

Subject: Re: Interference w/o Diffraction: Michelson Interferometer Practicality



I also wondered why no one had mentioned the Michelson Interferometer as
the answer to David Tam's original question of how to show interference
w/o diffraction.

It seemed to me that the idea of using the superposition of the front
and rear surface reflections from of a lens to show interference (w/o
diffraction) was really could be better achieved using a Michelson

But no one mentioned it. - jz

-----Original Message-----
From: [] On
Behalf Of Bill Norwood
Sent: Monday, October 26, 2009 11:34 AM
Subject: [tap-l] Interference w/o Diffraction: Michelson Interferometer

Hi Taplers,
- Our student lab interferometers have been idle for over a decade.
- I used to work with Michelson and Fabry-Perot interferometers in the
Lecture Demo context and did find it required a bit of extra effort to
make sure that the alignment was good for the lectures. But I assumed
that that would be part of what a student lab is all about - overcoming
apparatus manipulation challenges in order to get good data.
- The fact that no one to date has mentioned the Michelson
Interferometer in this 2-3-week-long thread suggests to me that the use
of Michelson Interferometers might have fallen into disfavor in student
laboratories. Is there any truth to this?
Many thanks for any info, Bill Norwood, U of MD at College Park

-----Original Message-----
From: [] On
Behalf Of David Tam
Sent: Thursday, October 22, 2009 11:18 PM
Subject: Re: [tap-l] interference without diffraction

Thanks everyone! I tried out some lenses and I got it to work

Cliff or anyone else - have you made a Fresnel biprism yourself out of
two prisms? I tried looking around but I don't have anything that
looks like one. I'm assuming the small angle doesn't need to be too
precise or too small (Hecht suggests 1 degree). I also wonder if
anyone ran into trouble with a gap that interferes with the central
maximum, before I go gluing stuff together.


On Mon, Oct 19, 2009 at 1:24 PM, WC Maddox
> From: WC Maddox
> For a bright two source interference pattern try this web site:
> Shine a laser on the
> of a test tube. The light reflected from the outside and inside
> will interfere. See " On a Demonstration of the Interference and
> of Light" in May 1973 issue of AJP for diagram and explanation.
> End Message
> David Tam wrote:
>> Hi everyone,
>> Does anyone do an effective demo (other than the ripple tank) to show
>> an interference pattern without any noticeable addition of a
>> diffraction pattern?
>> It appears no spacing of slits with a laser will create such a
>> AND keep the intensity high enough to be seen by a large lecture room
>> with the naked eye.
>> Any advice would be appreciated! Thanks,
>> David

From Mon Oct 26 12:32:00 2009