Double-layer silicon photonic crystal fiber tip temperature sensor

Abstract

Figure 1: (a) Fabrication process: (i) PC patterning to oxide (ii) 1st PC layer with partial undercut (iii) 2nd PC layer with complete release (iv) Support rim release and vapor HF oxide removal. (b) Si PC crosssection. The 1 st layer has a 820nm periodicity, 520nm hole diameter, and 500nm thickness. The 2 nd layer has a 820nm periodicity, 420nm hole diameter, and 400nm thickness. The gap between the layers is 1µm at maximum. (c) Sensor assembly setup (d) Top view of double-layer Si PC fiber tip sensor Abstract-We describe the fabrication of a double-layer silicon photonic crystal using self-aligned CMOS-compatible processes and its assembly on a single mode fiber using a wafer template and epoxy bonding. The fiber sensor has sharper resonances and higher temperature sensitivity than the previously-reported single-layer sensor. The new assembly method facilitates batchproduction of the sensor and allows for extension to high temperature measurement.