ARROW waveguide

Previously, Goddard and co-workers used anti resonant Fabry Perot reflectors to form antiresonant reflecting optical waveguides (ARROWs) in a gel layer13 14. 

Goddard, N. J. Hulme, J. Malins, C. Singh, K. Fielden, P. R., Asymmetric anti resonant reflecting optical waveguides (ARROW) as chemical sensors, Analyst 2002, 127, 378 382... 

Fig. 7 Fundamental and first mode of an antiresonant reflecting optica] waveguide (ARROW) waveguide. Layer thickness d and refractive indexes n are detailed for the external medium (ext), the core (c), the first cladding (1), the second cladding (2) and the substrate (sub)...

Table 2 Different materials employed in the fabrication of total internal reflection (TIR) and antiresonant reflecting optical waveguide (ARROW) waveguides...

In relation to other waveguides, ARROW structures offer some advantages by themselves for the development of chemical sensors. 

Fig. 9.2 Views of (a) a simple ridge waveguide and (b) a channel waveguide on a semiconductor substrate. The arrow indicates the direction of light propagation...

Fig. 14.4 Waveguide excitation of the OFRR resonant modes using (a) an ARROW clad wave guide and (b) a gold clad waveguide...

Equation (18.1) is known as the antiresonance condition for ARROW waveguides. For typical core dimensions of several microns, the last term under the square root can be neglected unless the cladding and core indices are approximately equal. 

Fig. 18.1 ARROW waveguides, (a) Side view of light ray propagating in original solid state ARROW19 (b) side view of ray propagating in hollow core ARROW (c) hollow core cross section with light polarization...

Fig. 18.2 Wavelength dependence of loss in ARROW waveguide for different antiresonant orders of cladding layers (see text)...

We have shown that antiresonant dielectric layers can be used to design low-loss liquid-core waveguides that are suitable for implementing planar sensor device geometries. The following sections will describe in more detail how the design principles laid out here were implemented in silicon-based LC-ARROW chips and used for optical sensing and detection of a wide variety of substances. 

Fig. 18.6 (a) ARROW based chip utilizing both solid and liquid core waveguides. The intersec tions of these two types of waveguides are highlighted, (b) Photograph of an ARROW based chip with fluid reservoirs attached... 

Optical losses in the liquid-filled ARROWs are typically measured using the cutback method. This measurement technique assumes optical transmission in the waveguide can be described according to... 

---