Abstract
For manipulating nanometric particles, we propose a photonic crystal waveguide cavity design with a waist structure to enhance resonance characteristic of the cavity. For trapping a polystyrene particle of 50 nm radius on the lateral side of the waist, the optical force can reach 2308 pN/W with 24.7% signal transmission. Threshold power of only 0.32 mW is required for stable trapping. The total length of the device is relatively short with only ten photonic crystal periods, and the trapping can occur precisely and only at the waist. The designed cavity can also provide particle detection and surrounding medium sensing using the transmission spectrum with narrow linewidth. The simulated figure of merit of 110.6 is relatively high compared with those obtained from most plasmonic structures for sensing application. We anticipate this design with features of compact, efficient, and versatile in functionality will be beneficial for developing lab-on-chip in the future.
Highlights
To date, manipulating tiny fragile objects by optical forces with contactless and nondestructive features has inspired many applications ranging from physics to biology
The calculated value is 188.0 nm/RIU and the corresponding figure of merit (FOM), defined as sensitivity divided by spectral linewidth, is 110.6, which is relatively high compared with those obtained from most plasmonic structures for sensing application [25]
We propose a photonic crystal waveguide cavity design with a waist structure for trapping particles in the near field region on a chip
Summary
To date, manipulating tiny fragile objects by optical forces with contactless and nondestructive features has inspired many applications ranging from physics to biology. By designing structures to well utilize evanescent waves, tiny objects can be manipulated without the massive focusing system This starts a new branch of integrating particle manipulating system on a chip. We intend to trap particles on the side of cavity instead of on the top or in the slot With both the waist structure and resonant characteristic, optical field distributing around the side of the cavity will be very strong. Occurrence of the trapping can be known by the peak shift of transmission spectrum instead of using a high resolution microscope These unique properties and benefits of our design are evaluated numerically and compared to reference structures in this study
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
