Question

In the questions that follow, assume that all angles are measured counterclockwise from the +x axis in the direction of the +y axis.

Part A

A beam of polarized light with intensity I0 and polarization angle θ0 strikes a polarizer with transmission axis θTA. What angle θ should be used in Malus's law to calculate the transmitted intensity I1? This process is illustrated in the figure (Figure 2) , where the polarization of the light wave is visually illustrated by a magenta double arrow oriented in the direction of polarization, the transmission axis of the polarizer is represented by a blue double arrow, and the direction of motion of the wave is illustrated by a purple arrow.

Part B

What is the polarization angle θ1 of the light emerging from the polarizer?

Part C

If I0 = 80.0 W/m2 , θ0 = 29.0 degrees , and θTA = 48.0 degrees , what is the transmitted intensity I1?

Express your answer numerically in watts per square meter .

Answer 1

(A) The angle θ is equal to the difference in transmission angle θ\lambda_{i} and polarizing angle θ₀. θ=θJ A-θ₀ (B) The polarizing angle θ₁ is equal to the transmission angle θ\text {TA }. θ₁=θT A (C) The angle θ is, \begin{aligned} θ &=θπ i-θ₀ \\ &=48°-29° \\ &=19° \end{aligned} According to Malus law, the intensity I₁ is, \begin{aligned} I₁ &=I₀ \cos ² θ \\ &=(80 W / m²) \cos ² 19° \\ &=71.5 W / m² \end{aligned}