A theoretical study of a nano-opto-mechanical sensor using a photonic crystal-cantilever cavity

TitleA theoretical study of a nano-opto-mechanical sensor using a photonic crystal-cantilever cavity
Publication TypeJournal Article
Year of Publication2012
AuthorsMao DP, Liu P, Ho KM, Dong L
Journal TitleJournal of Optics
Volume14
Pages075002
Date Published07
Type of ArticleArticle
ISBN Number2040-8978
Accession NumberWOS:000306272400003
KeywordsBIOSENSORS, cantilever, microcavity, optical cavity, photonic crystals, reflection, RESONANCE, SENSOR, STRESS
Abstract

In this simulation study, integration of a nanocantilever inside a two-dimensional (2D) photonic crystal (PC) cavity resulted in a unique photonic crystal-cantilever cavity (PC3), where the cantilever served as a tunable mechanical defect of the PC slab. Strong nano-opto-mechanical interactions between the cantilever and the defect-mode field inside the PC3 gave rise to a high sensitivity of the resonance wavelength to surface stress-induced cantilever deflection. Mechanical and optical responses of the PC3 to surface stress changes on the cantilever surface were studied by using a finite-element method (FEM) and a finite-difference time-domain (FDTD) method, respectively. Theoretical analysis revealed that the devised PC3 sensor could resolve a conservative minimum surface stress at the level of similar to 0.8 mN m(-1), representing state-of-the-art cantilever sensor performance. Also, the PC3 sensor design used an ultracompact structure with an on-chip optical length of only several microns, while a conventional reflected laser beam detection scheme requires a similar to 1 m long free-space optical path.

URL<Go to ISI>://WOS:000306272400003
DOI10.1088/2040-8978/14/7/075002
Alternate JournalJ. Opt.