A single beam of coherent light ( = 633 10-9 m) is incident on two glass slides, which are touching at one end and

A single beam of coherent light (λ = 633 ˆ™ 10-9 m) is incident on two glass slides, which are touching at one end and are separated by a 0.0200-mm-thick sheet of paper on the other end, as shown in the figure. Beam 1 reflects off the bottom surface of the top slide, and beam 2 reflects off the top surface of the bottom slide. Assume that all the beams are perfectly vertical and are perpendicular to both slides, that is, the slides are nearly parallel (the angle is exaggerated in the figure); the beams are shown at angles in the figure so that they are easier to identify. Beams 1 and 2 recombine at the location of the eye. The slides are 8.00 cm long. Starting from the left end (x = 0), at what positions, xbright, do bright bands appear to the observer above the slides? How many bright bands are observed?

Reflected light Incident light 633 nm Air 0.0200 mm n_ r.so! Paper sheet 1.00 mm n 1.50 8.00 cm