Microfabricated Otto chip device for surface plasmon resonance-based optical sensing

Abstract

Surface plasmon resonance (SPR) based sensors are usually designed using the Kretschmann prism coupling configuration in which an input beam couples with a surface plasmon through a thin metal film. This is generally preferred by sensor developers for building planar devices instead of the Otto prism coupling configuration, which, for efficient coupling, requires the metal surface to be maintained at a distance on the order of the wavelength from the input prism surface. In this paper, we report on the microfabrication and characterization of an Otto chip device, which is suitable for applications of the SPR effect in gas sensing and biosensing.

Pressure sensing by surface plasmon resonance in the Otto configuration

“…A silicon wafer was used as substrate to fabricate several devices. First, an initial cavity with a depth of 2.5 m was formed on the silicon substrate using a deep reactive ion etching (DRIE) process [1], with a thin positive photoresist (PR) used as an etch mask, as illustrated in Fig.1. Then, the PR was removed using an oxygen plasma etcher.…”

“…We have recently reported on the fabrication of an Otto chip device [1], capable of exhibiting the surface plasmon resonance -SPR -effect [2]- [3]. The device comprises a closed structure having a well-defined gap distance between the inner surface of a quartz window and the metal surface.…”

“…By use of the traditional prism coupling configuration [2]- [3], an input light beam can be used to excite a surface plasmon on the metal surface. The critical step in fabricating such a structure is the sealing without offsetting the gap distance, which is a critical parameter to define the degree of coupling between the incoming beam and the surface plasmon on the metal [1].…”

Planar Dual-Band ISM Antenna for Wireless Sensors

“…A planar dual-band antenna with multiband has the reliability and simplicity required to be integrated into chemical sensors heads, operating at infrared wavelengths [1], and respective optoelectronics in a package. ISM-band antennas are usually employed to undertake high quality data transmission using unlicensed bands.…”

Silicon-on-quartz bonding based SPR chip

“…Thus, the adhesion layer between the metal and substrate does not affect the quality factor of the SPR effect. Additionally the channel height can be thinner compared to SPR chips based on the Kretschmann coupling configuration [14]. Furthermore, opaque materials such as silicon, which has a number of chemical and mechanical advantages, can be used as a substrate.…”