A monochromatic laser beam of intensity 1,- 560 W/m2 is polarized in the propaga
ID: 2038385 • Letter: A
Question
A monochromatic laser beam of intensity 1,- 560 W/m2 is polarized in the propagates in the positive z-direction. This beam is incident upon a makes an angle of 45 degrees with the x-axis as shown. Following the polarizers; the transmission axis of the first polarizer is aligned with axis of the and ind quarter-wave plate whose fast axis quarter-wave plate are two the x-axis, while the transmison second polarizer makes an angle of 0, -77 degrees with the positive x axis. Side Viw Polarized along y End Viaw 7) What is Imid, the intensity of the beam immediately following the polarizer whose transmission axis is aligned with the x-axis? W/m2 8) What is Isinal the intensity of the beam immediately following the last polarizer? W/m 9) What is the ratio of Ey,tinal, the maximum value of the y-component of the electric field immediately following the last polarizer, to Fo, the amplitude of the electric field oscillations in the incident polarized beam? 10) The positions of the quarter-waveplate and the last polarizer are now interchanged. What is fanew the intensity of the beam after passing through the new arrangement of the two polarizers and the quarter-wave plate? Side Vine Polarized along y ay ya End View W/mExplanation / Answer
7)
I1 = Io*cos^2(45)
= 560*cos^2(45)
= 280 W/m^2
Imid = I1*cos^2(45)
= 280*cos^2(45)
= 140 W/m^2
8) I_final = I_mid*cos^2(71)
= 140*cos^2(71)
= 14.8 W/m^2
9) Ey_Final/Eo = sqrt(I_final/Io)
= sqrt(14.8/560)
= 0.163
10) I1 = Io*cos^2(90-71)
= 560*cos^2(19)
= 500.6 W/m^2
I_mid = I1*cos^2(71)
= 500.6*cos^2(71)
= 53.06 W/m^2
I_final = I_mid*cos^2(45)
= 53.06*cos^2(45)
= 26.5 W/m^2