3
$\begingroup$

To explain polarisation, my book gives an example of a transverse wave in a string, and explains as:

Since each point on the string moves on a straight line, the wave is also referred to as a linearly polarised wave. Further, the string always remains confined to the x-y plane and therefore it is also referred to as a plane polarised wave

The image given is somewhat like this: enter image description here

The definitions for both these terms are different, so it seems to me that they are not same. But I wasn't able to find an example which illustrates the difference between these two.

I found this Quora question, but the answers don't seem convincing.

So what exactly is the difference between a linearly polarised wave and a plane-polarised wave? Because according to me, a linearly polarised wave will oscillate in only one plane.

$\endgroup$
2
  • 4
    $\begingroup$ I've always taken them as synonymous. The main distinction is between plane [linear] and circularly polarized light, which doesn't oscillate in any one plane. $\endgroup$ Commented Feb 22, 2019 at 21:22
  • 1
    $\begingroup$ linear polarisation only talks about direction of oscillation of electric field for example y polarised light has it electric field amplitude only in y-direction and it direction propogation is not specified . we need plane of polarisation to specify a waves oscillation as well as direction of propogation. y polarised light can propogate in x-direction or in z- direction. this distinction (linear polarisation and plane polarisation ) is required to know direction of oscillation as well as direction of propogation $\endgroup$
    – teja
    Commented Jun 3, 2019 at 6:06

2 Answers 2

2
$\begingroup$

Linearly polarized wave is same as plane polarized wave. Why we call it linearly polarized ? Because oscillation taking place along a line. Why we call it plane polarized ? Since oscillation taking place along one axis & the wave is forward in motion along another axis. Two axes are used , so called plane.

$\endgroup$
0
$\begingroup$

Linearly polarized wave Oscillate in a single plane and the magnitude of electric field vector varies sinusoidally as a function of time.

Circularly polarized wave have their magnitude of electric field vector constant, but their phase change periodically as a function of time.(i.e. the electric field vector rotate periodically as a function of time)

$\endgroup$
2
  • 1
    $\begingroup$ In your answer, shouldn't it be displacement(or something else) varies sinusoidally as a function of time instead of amplitude varies sinusoidally as a function of time $\endgroup$
    – Eagle
    Commented Feb 23, 2019 at 12:03
  • $\begingroup$ I'm sorry. I had written amplitude instead of writing electric field vector. $\endgroup$
    – walber97
    Commented Feb 24, 2019 at 6:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.