A 200 mW horizontally polarized laser beam

In summary: Use that to find the transmitted power.No, I'm sorry, I'm still not understanding...I'm not sure I'm familiar with what the "intensity" would be. Could you possibly explain it a little more?In summary, a 200 mW horizontally polarized laser beam passes through a polarizing filter with an axis 25 degrees from vertical. The incident power is given as 200 mW, and the transmitted intensity is governed by the Law of Malus. Using this law, the transmitted power can be calculated by multiplying the incident power by the cosine of the angle between the incident wave and the filter's axis, which in this case is 65 degrees. This results in a transmitted power of approximately 84.
  • #1
jlmessick88
32
0

Homework Statement


A 200 mW horizontally polarized laser beam passes through a polarizing filter whose axis is 25 degrees from vertical.

What is the power of the laser beam as it emerges from the filter?
P=mW

Homework Equations



E (transmitted) = E (incident)cos()

The Attempt at a Solution


200= E(incident) cos (25)
E(incident) = 2.206*10^2

Not sure if this is correct..this is my last attempt at the question, need to know if I'm approaching this correctly at all??
Thanks!
 
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  • #2
jlmessick88 said:

The Attempt at a Solution


200= E(incident) cos (25)
E(incident) = 2.206*10^2
(1) Don't mix up the amplitude (E) with the intensity (what you want), which is governed by the Law of Malus. See: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/polcross.html#c3"
(2) The incident power is given; that's what the 200 mW refers to.
(3) Note that the incident wave is horizontally polarized, while the angle given is with respect to the vertical.
 
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  • #3
so instead, if i understand you...it should be 200*cos(25) = 1.81*10^2?
 
  • #4
jlmessick88 said:
so instead, if i understand you...it should be 200*cos(25) = 1.81*10^2?
No, but you're getting closer. Read all three of my points, not just the second one.
 
  • #5
so in regards to #3...instead of being 25 degrees...it would be 65 degrees?? if I'm picturing this correctly
 
  • #6
jlmessick88 said:
so in regards to #3...instead of being 25 degrees...it would be 65 degrees?? if I'm picturing this correctly
Yes, that's what I would say.
 
  • #7
200*cos(65) = 84.5 =/= An answer Mastering Physics will mark as right.
 
  • #8
See Doc Al's link to the Law of Malus in Post #2. What does the link say about the transmitted intensity? (Don't confuse it with the electric field.)
 

FAQ: A 200 mW horizontally polarized laser beam

What is a 200 mW horizontally polarized laser beam?

A 200 mW horizontally polarized laser beam is a type of laser beam that emits light with a power of 200 milliwatts and has a polarization orientation that is parallel to the horizon or any flat surface. This means that the electric field of the laser light oscillates in a horizontal direction.

How is the power of a laser beam measured?

The power of a laser beam is typically measured in milliwatts (mW) or watts (W). This measurement is based on the rate at which the laser beam delivers energy per unit of time. For example, a 200 mW laser beam delivers 200 millijoules of energy per second.

What is the importance of polarization in a laser beam?

Polarization plays a crucial role in the behavior and properties of a laser beam. The polarization of a laser beam determines the direction in which the electric field oscillates, which affects the beam's intensity, angle of refraction, and interference patterns. Additionally, polarization is important in applications such as communications, microscopy, and optical data storage.

Is a horizontally polarized laser beam more powerful than a vertically polarized one?

No, the polarization of a laser beam does not affect its power. A horizontally polarized laser beam with a power of 200 mW has the same strength as a vertically polarized laser beam with the same power. The polarization only determines the direction of the electric field's oscillation, not the beam's overall power.

What are some applications of a 200 mW horizontally polarized laser beam?

A 200 mW horizontally polarized laser beam has various applications in different fields, including telecommunications, laser cutting, laser engraving, laser pointers, and holography. It is also commonly used in research laboratories for experiments and measurements due to its relatively high power output and stable polarization orientation.

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