Full text loading...
(a) Schematic diagram of the microfluidic channel used for thermally generated optical waveguides. The length, width, and height of the channel are 5 mm, , and , respectively. The dotted line shows the boundary between hot and cold liquids under laminar flow conditions. (b) Graph of refractive indices measured using benchtop Bausch and Lomb refractometer as a function of temperature for: (i) ethylene glycol, (ii) ethanol, (iii) deionized water, and (iv) perfluoro(methyldecalin). The average slopes or TO coefficients are (ethylene glycol), (ethanol), (water), and [perfluoro(methyldecalin)], respectively.
(a) and (b) Plots of average intensity (arbitrary units, a.u.) of a digital micrograph taken of the light output of the water waveguide at the outlet of the microfluidic channel viewed through the transparent window for nonwaveguiding and waveguiding under various rates of flow and temperature settings. The insets show the digital micrographs used as the sources for the plots (data were smoothed prior to integration). In each case, the core was water at 21 °C and the cladding was water heated to 80 °C. Total rates of flow were (a) and (b), respectively. (c) Plot of intensity ratio at the light output as a function of total flow rate . (d) Plot of intensity ratio as a function of temperature in the cladding region (total rate of flow). The error bars in both (c) and (d) were smaller than the size of the symbols.
Simulated two-dimensional distributions of refractive index in a 5 mm long waveguide formed by water at total rates of flow of (a) and (b), and and . Plot of the refractive index as a function of distance from the center of the waveguide in the transverse direction for three positions along a waveguide (in direction)—i.e., the beginning (solid line), the middle (dashed line), and the end (dotted line) of the channel at total rates of flow of (c) and (d). The residence times are 0.12 s in (a) and 0.012 s in (b), respectively.
Article metrics loading...