The term ”optofluidics” was coined in 2003 to define an emergent research field that focuses on combining microfluidic and optical technology. In the space of 5 years, this terminology has become widely adopted and applied as a categorical descriptor for a large number of research directions. The input of the term “optofluidic” in Google yields around 24,000 webpage results. It is certainly true that some of the research projects that have adopted “optofluidics” as part of their descriptor could have evolved independently. After all, we can find examples of research projects that combine fluidics and optics that predated the genesis of “optofluidics”— the electrowetting lens (Chap. 9) is an excellent example. However, the large number and wide variety of “optofluidic”-themed research projects that have cropped up over the past 5 years indicate that the definition of optofluidics as a field is causally linked to the proliferation of at least a few such projects. Once the seed idea of combining the advantages of microfluidics and optics was formally defined, it did not take long for the concept to take hold in the minds of researchers and germinate prolifically. The optofluidic microscope (Chap. 11) and optofluidic lasers (Chap. 10) are some of the projects for which causal links between the birth of the term “optofluidics” and the initiation of the projects can be traced.