Page 297 - Optofluidics Fundamentals, Devices, and Applications

CHAPTER 12

Optofluidic

Resonators

Dominik G. Rabus
Baskin School of Engineering, University of California, Santa Cruz

ptofluidic resonators are a new class of devices that have
emerged recently with the implementation of resonant opti-
Ocal structures in fluidic channels. There are several reasons
why this resonator-fluidic merger has gained increasing resonance,
the first one being the focus on sensors and especially biosensors
where it is inevitable to analyze substances in liquids. The other rea-
son is the advent of optofluidic light sources where integrated reso-
nators are needed to provide feedback and thus enable higher-output
powers as it is known from conventional integrated light sources.

12-1 Optofluidic Resonators
This chapter is dedicated to provide an overview on optofluidic reso-
nators, especially photonic crystal, Bragg grating, ring resonators,
and Fabry-Perot resonators. Suitable fabrication techniques will be
briefly explained and highlighted. Examples on demonstrated reso-
nator devices will conclude this chapter.
12-1-1 Resonators
Optofluidic resonators realized so far in different material systems
are, for example, photonic crystals [1], Bragg gratings [2], ring resona-
tors [3], and Fabry-Perot resonators [4]. In order to design and fabri-
cate devices, the basic theories of selected resonator structures are
given in this section.
Photonic crystals have emerged recently and have found numerous
applications like the use of optofluidic photonic crystal fiber. The poten-
tial of photonic crystals was first realized in 1987 by Eli Yablonovitch.

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