Optofluidic waveguides: I. Concepts and implementations

Abstract

We review recent developments and current status of liquid-core optical waveguides in optofluidics with emphasis on suitability for creating fully planar optofluidic labs-on-a-chip. In this first of two contributions, we give an overview of the different waveguide types that are being considered for effectively combining micro and nanofluidics with integrated optics. The large number of approaches is separated into conventional index-guided waveguides and more recent implementations using wave interference. The underlying principle for waveguiding and the current status are described for each type. We then focus on reviewing recent work on microfabricated liquidcore antiresonant reflecting optical (ARROW) waveguides, including the development of intersecting 2D waveguide networks and optical fluorescence and Raman detection with planar beam geometry. Single molecule detection capability and addition of electrical control for electrokinetic manipulation and analysis of single bioparticles are demonstrated. The demonstrated performance of liquidcore ARROWs is representative of the potential of integrated waveguides for on-chip detection with ultrahigh sensitivity, and points the way towards the next generation of high-performance, low-cost and portable biomedical instruments.

Optofluidic wavelength division multiplexing for single-virus detection

“…A particle labeled for excitation at this wavelength creates six signal emission peaks that are equally spaced in time as it flows through the channel at constant speed. Emitted photons are captured and routed to a detector if the channel also acts as a liquidcore optical waveguide (19)(20)(21)(22). This type of multispot excitation can be used to significantly enhance the signal-to-noise ratio of a fluorescence assay (13,23).…”

Mesoscale cavities in hollow-core waveguides for quantum optics with atomic ensembles

“…Hollow core AR-ROW waveguides were first demonstrated by Delonge and Fouckhardt in 1995 [29]. Since then ARROWs have found applications in lasers [30], single-molecule detection [31], and have been used to demonstrate electromagnetically induced transparency and slow light on a chip [6]. At the same time, an alternative approach to on-chip hollow-core waveguides, based on hollow core waveguides utilizing high-contrast subwavelength gratings (HCSWG), has been recently demonstrated by Yang et al [32].…”

Modular Platforms for Optofluidic Systems

“…Furthermore, the basic elements of optical platforms have been developed with optofluidic principles, namely waveguides [88][89][90][91][92][93][94] and optical switches [95][96][97][98][99]. The optofluidic switch has even reached industrial level (Agilent Photonic Switching Platform).…”