Page 633 - Introduction to Information Optics

Chapter 11 Information Display with Optics

1 2
Ting-Chung Poon and Taegeun Kim
'OPTICAL IMAGE PROCESSING LABORATORY
(www.ee.vt.edu/ ~ oiplab/),
BRADLEY DEPARTMENT OF ELECTRICAL AND
COMPUTER ENGINEERING,
VIRGINIA POLYTECHNIC INSTITUTE AND
STATE UNIVERSITY (VIRGINIA TECH),
BLACKSBURG, VIRGINIA 24061, USA
2
DEPARTMENT OF OPTICAL ENGINEERING,
SEJONG UNIVERSITY,
98 KUNJA-DONG, KWANGJIN-KU,
SEOUL, 143-747, KOREA

11.1. INTRODUCTION

From conventional two-dimensional (2-D) projection display to 3-D holo-
graphic display, techniques using photographic films have been extremely well
developed. Photographic films have shown good optical properties in modula-
ting certain properties of optical wavefronts, like amplitude or phase. However,
in spite of good optical properties, photographic films have a critical drawback
in time delay. Since they require chemical processing, long time delay is
required from information storage to display. In modern display applications,
there are increased needs for a real-time device for optical information
processing; such a device is often called a spatial light modulator (SLM).
Examples of SLMs are acousto-optic modulators and electro-optic modula-
tors. In this chapter, we will concentrate on these two types of modulators.
We first discuss 2-D information display using acousto-optic (AO) modula-
tors in Sec. 11.2. Sections 11.2.1 to 11.2.3 discuss the rudiments of acousto-
optics and some of its applications, such as intensity modulation and deflection
of laser. In Sec. 11.2.4, we illustrate how laser TV display can be achieved using
AO devices. Since the real world is 3-D, in which the human visual system can
sense it, this makes a real-time 3-D display an ultimate goal in the area of
information display. Holography has been considered a most likely candidate
for this task. In Sec. 11.3, we discuss 3-D display. Within the section, the
principles of holography are first discussed, which will then be followed by two