Analysis for an Improved Nanomechanical Microcantilever Sensor on Optical Waveguides

Abstract

An analysis model for an optical waveguide microcantilever sensor is developed combining the optical and mechanical models. An improved optical waveguide microcantilever sensor with a buffer is provided and taken as an example to explore using the analysis model. A systematic and detailed discussion about the couplers for the input waveguide to optical waveguide cantilever and the optical waveguide cantilever to the output waveguide of the improved waveguide cantilever sensor is presented. The sensitivity of an improved optical waveguide cantilever sensor is evaluated by analyzing the input/output waveguide, buffer, microcantilever, and gap. An improved optical waveguide microcantilever sensor by adding a buffer shows a sensitivity of 5.7 × 10 −4 nm −1 , which is improved by 51.3%, compared with a conventional optical waveguide microcantilever sensor. The design of an optical waveguide cantilever sensor is a trade-off of different design parameters. These will be helpful for the study of an optical waveguide cantilever sensor.

Analysis of ARROW Waveguide based Microcantilever for Sensing Application

“…The average sensitivity with our work is 73.78 nm/RIU. The obtained sensitivity is comparable with the sensitivity values obtained in article [5]. The variation in the refractive index of the material is denoted as refractive index unit (RIU).…”

“…The selection of the dimension of the device is very important in the ARROW waveguide design. The selection was thickness of each layer is by considering the below equation (5) and (6). The first cladding layer thickness ( 1 ) is given by the below equation (5) [30]…”

“…The bending of the cantilever is characterized by the functional area. The interaction of the molecules on the surface of the cantilever waveguide leads to surface stress ∆ , this intern leads to deflection in the waveguide and is given in the equation ( 4) [5].…”

“…The sensor developed has sensitivity of 5.7 x 10 -4 nm -1 . The modelling method involved in the design was finite element method (FEM) [5]. Nanomechanical sensor also used for detection of femtogram mass using photo thermal actuation.…”