Page 267 - Optofluidics Fundamentals, Devices, and Applications

CHAPTER 10

Optofluidic Dye

Lasers

Anders Kristensen
Department of Micro and Nanotechnology, Technical University of Denmark

N. Asger Mortensen
Department of Photonics Engineering, Technical University of Denmark

10-1 Introduction
Lab-on-a-chip applications call for a reconsideration of light sources.
The light must be either coupled into, or generated on the chip itself.
Application of external light sources has the advantage that a large
variety of light sources are readily available, and often at reasonable
price. However, in any product involving integrated optics, the cou-
pling of light onto microchips represents a major challenge, being
both labor-intensive and costly. On-chip light generation offers an
alternative route. In lab-on-a-chip microsystems, light sources, or
even lasers, can be integrated in a simple way by infiltrating dedi-
cated microfluidic components with liquid light emitters, for exam-
ple, liquid laser dye solutions (see Fig. 10-1). With this optofluidic
approach the on-chip light sources are basically added without add-
ing further steps in the fabrication procedure [1]. Furthermore, there
is by virtue no alignment issues with the light sources, as all optical
components are defined in the same lithography process, and
thereby benefit from the high placement accuracy of modern micro-
lithography.

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