Page 488 - Introduction to Information Optics

Exercises 473
is read out by a laser beam. The reconstructed holographic image is
detected by a CCD with the same 1000 x 1000 pixels, as shown in the
2 6
following figure. Each pixel is 10 x 10 /mi , and the sensitivity is 10
2
W/cm . If the diffraction efficiency of the hologram is 10%, what is the
minimum laser power required to read the memory?

Zero Order Beam
Hologram

CCD

L
-' Reconstructed Beam
Readout Beam

8.34 We have a sinusoidal pattern on a transmissive plate with period 1/4 and
unity contrast. The plate is illuminated with a uniform light. What is the
contrast at the plane A/100,1/10,1/2,1, and 101 away from the plate?
8.35 Repeat Exercise 8.34 for a sinusoidal pattern with period 1/20,