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Title: Experimental Comparison of Slow Light and Subwavelength Waveguide Interferometer Sensors
We experimentally demonstrate slow light photonic crystal waveguide (PCW) and subwavelength waveguide (SWWG) loop terminated Mach-Zehnder interferometer (LT-MZI) sensors in a foundry-fabricated silicon-on-insulator (SOI) platform. We compare the experimental results on sensitivity and limit of detection (LOD) on the interferometer sensors with microcavity-type sensors. We show experimentally that 2-D PCW interferometers have higher phase sensitivities than SWWGs of the same length. Based on experimental results, 20- μ m-long 2-D PCW LT-MZI sensors and 200- μ m-long SWWG LT-MZI sensors achieve an LOD of 3.4×10−4 and 2.3×10−4 RIU, respectively, with nearly the same insertion losses in foundry-fabricated devices. We show that by considering the various sources of loss in our benchtop fiber-to-fiber photonic integrated circuit measurement system, it will be possible to reach 10−7 LOD in both slow light PCW and SWWG-based LT-MZI sensors with on-chip integrated light sources and detectors. We show via simulations and experiment that the LOD of a 20- μ m-long slow light PCW LT-MZI is equivalent to that of a 100- μ m-long SWWG LT-MZI, thus enabling more compact LT_MZI sensors when using slow light PCWs versus SWWGs  more » « less
Award ID(s):
2210707 2315085
PAR ID:
10630195
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
IEEE Sensors Journal
Date Published:
Journal Name:
IEEE Sensors Journal
Volume:
24
Issue:
20
ISSN:
1530-437X
Page Range / eLocation ID:
32023 to 32033
Subject(s) / Keyword(s):
Biosensors, chemical sensors, loop terminated Mach–Zehnder interferometer (LT-MZI), optical interferometer sensors, photonic crystal waveguide (PCW), silicon photonics, subwavelength waveguide (SWWG)
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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