TY - JOUR
T1 - Three-Dimensional Printed Polymer Waveguides for Whispering Gallery Mode Sensors
AU - Wei, Heming
AU - Amrithanath, Abhishek K.
AU - Krishnaswamy, Sridhar
N1 - Funding Information:
Manuscript received October 13, 2017; revised January 22, 2018; accepted January 22, 2018. Date of publication January 25, 2018; date of current version February 12, 2018. This work was supported by the Office of Naval Research through under Grant N00014-15-1-2935 and Grant N00014-16-1-3021. (Corresponding author: Heming Wei.) The authors are with the Department of Mechanical Engineering, Center for Smart Structures and Materials, Northwestern University, Evanston, IL 60208 USA (e-mail: hmwei@northwestern.edu; abhishekamrithanath2020@ u.northwestern.edu; s-krishnaswamy@northwestern.edu).
Publisher Copyright:
© 2017 IEEE.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Whispering gallery mode (WGM) microresonators are widely exploited for highly sensitive sensing applications due to their ultrahigh quality (Q) factor enabling single-particle detection. The WGM surface-confined resonant light recirculates around the resonator, allowing the light to interact with analytes over several round trips, which enhances the sensitivity of detection. However, the stability of efficient coupling of WGMs to ingress-egress waveguides for lab-on-chip has been problematic. The typical way to achieve WGM coupling is to use a tapered optical fiber or a prism, which makes the device either fragile or bulky, and is not conducive to sensor integration that can lead to robust lab-on-chip devices. In this letter, we demonstrate three-dimensional (3D) fabricated polymer waveguides that can be integrated and provide evanescent coupling to silica WGM microspheres without sacrificing Q factor. By mechanically connecting the waveguides to the microcavity, we can control the coupling to the resonator and the mechanical stability of the 3D lab-on-chip sensor is greatly improved. This provides a pathway to enhance the stability of WGM coupling for sensor integration.
AB - Whispering gallery mode (WGM) microresonators are widely exploited for highly sensitive sensing applications due to their ultrahigh quality (Q) factor enabling single-particle detection. The WGM surface-confined resonant light recirculates around the resonator, allowing the light to interact with analytes over several round trips, which enhances the sensitivity of detection. However, the stability of efficient coupling of WGMs to ingress-egress waveguides for lab-on-chip has been problematic. The typical way to achieve WGM coupling is to use a tapered optical fiber or a prism, which makes the device either fragile or bulky, and is not conducive to sensor integration that can lead to robust lab-on-chip devices. In this letter, we demonstrate three-dimensional (3D) fabricated polymer waveguides that can be integrated and provide evanescent coupling to silica WGM microspheres without sacrificing Q factor. By mechanically connecting the waveguides to the microcavity, we can control the coupling to the resonator and the mechanical stability of the 3D lab-on-chip sensor is greatly improved. This provides a pathway to enhance the stability of WGM coupling for sensor integration.
KW - 3D polymer waveguides
KW - Whispering gallery modes
KW - direct laser writing
KW - integrated optical devices
KW - silica microsphere
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U2 - 10.1109/LPT.2018.2798539
DO - 10.1109/LPT.2018.2798539
M3 - Article
AN - SCOPUS:85040968787
SN - 1041-1135
VL - 30
SP - 451
EP - 454
JO - IEEE Photonics Technology Letters
JF - IEEE Photonics Technology Letters
IS - 5
ER -