Page 78 - Optofluidics Fundamentals, Devices, and Applications

CHAPTER 4

Optofluidic Optical

Components

Uriel Levy
Department of Applied Physics, The Benin School of Engineering and Computer
Science, The Hebrew University of Jerusalem, Jerusalem, Israel

4-1 Introduction
The term optofluidic optical component (OOC) refers to a class of
devices where micro-/nanofluidics is used to form an optical com-
ponent by controlling its geometry, refractive index, and its optical
functionalities, for example, transmission, reflection, absorption, or
scattering. To date, the most widespread OOC is probably the liquid
crystal display that is being incorporated in large variety of devices,
including, for example, computers and TV screens, watches, and
cell phones. In contrast to the liquid crystal display, which is avail-
able for many years, most of the OOCs are being investigated and
developed only in recent years, and are expected to lie at the center
of the emerging field of optofluidics, with the vision of integrating
variety of OOCs to form miniaturized, on-chip optofluidic systems
with potential applications in medicine, biology and biotechnology,
chemical synthesis and controlled reactions, signal processing, com-
munication, imaging, projection, storage, and military applications.
Progress in optofluidics is now well documented by several recent
review papers [1–3].
A key motivation for the implementation of OOCs is their ease of
fabrication by rapid prototyping as well as the flexibility in forming
variety of geometries and refractive index combinations, allowing the
realization of almost any desired optical functionality. One of the fun-
damental terms in optics is the “optical path length.” According to
Fermat the path taken between two points by a ray of light is the path
that can be traversed in the least time (the more accurate version of

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