Go Back   Physics Help Forum > High School and Pre-University Physics Help > Light and Optics

Light and Optics Light and Optics Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Feb 14th 2010, 05:25 PM   #1
Junior Member
 
Join Date: Feb 2010
Location: UK
Posts: 17
Question about a polarising filter.

DOUBLE POST, SORRY


Explain how you could use a polarising filter to find out which surfaces polarise light when they reflect it. Brewster found that the surfaces that do this reflect completely polarised light when the tangent of the angle of incidence equals their refractive index. Calculate the angle of incidence needed to reflect completely polarised light for glass of refractive index
1.5.
What is the angle of reflection for this light?
The reflected light is only about 8%. The rest enters the glass. How might you boost this % using glass reflective surfaces only?

Please explain how to do all parts of this question.

All help very much appreciated! Don't even know where to start on this
Thanks

Last edited by George321; Feb 14th 2010 at 05:42 PM.
George321 is offline   Reply With Quote
Old Mar 1st 2010, 02:24 AM   #2
Senior Member
 
Join Date: Dec 2008
Location: Udupi, Karnataka, India
Posts: 292
Observe the reflected light form the surface through the polarizing filter. Now rotate the filter. If you see the variation in the intensity of the light, then the reflected light is polarized. At one instant, if you see zero intensity, the light is completely polarized.
Use formula μ = tan(θp)
You can increase the % by using stack multiple plates.
sa-ri-ga-ma is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Light and Optics

Tags
filter, polarised, polarising, polarising filter, question, reflect, refractive index



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Which optical component (spatial filter) can achieve this? sidharth52 Light and Optics 1 Dec 26th 2015 09:11 AM
Tubular Optical Filter jamesadrian Light and Optics 2 Dec 26th 2013 05:27 PM
How to filter out blue light? Aegimius Light and Optics 3 Oct 7th 2010 04:35 AM
coffee filter terminal speeds rstuff Kinematics and Dynamics 3 Nov 22nd 2009 11:34 PM
building H-alpha solar filter setarehkoochak Kinematics and Dynamics 1 Feb 24th 2009 09:51 PM


Facebook Twitter Google+ RSS Feed