Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Surface plasmon resonance-based highly sensitive optical touch sensor with a hybrid noise rejection scheme

Not Accessible

Your library or personal account may give you access

Abstract

A surface plasmon resonance (SPR)-based optical touch sensor structure is proposed that provides high switch sensitivity and requires a weak activating force. Our proposed SPR-based optical touch sensor is arranged in a compact Kretschmann–Raether configuration in which the prism acting as our sensor head is coated with a metal nanofilm. Our optical-based noise rejection scheme relies on wavelength filtering, spatial filtering, and high reflectivity of the metal nanofilm, whereas our electrical-based noise reduction is obtained by means of an electrical signal filtering process. In our experimental proof of concept, a visible laser diode at a 655  nm centered wavelength and a prism made from BK7 with a 50 nm thick gold layer on the touching surface are used, showing a 7.85  dB optical contrast ratio for the first touch. An estimated weak mechanical force of <0.1  N is also observed that sufficiently activates the desired electrical load. It is tested for 51 operations without sensor malfunction under typical and very high illumination of 342  and 3000 lx, respectively. In this case, a measured average optical contrast of 0.80  dB is obtained with a ±0.47  dB fluctuation, implying that the refractive index change in a small 3.2% of the overall active area is enough for our SPR-based optical touch sensor to function properly. Increasing optical contrast in our SPR-based optical touch sensor can be accomplished by using a higher polarization-extinction ratio and a narrower-bandwidth optical beam. A controlled environment and gold-coated surface using the thin-film sputtering technique can help improve the reliability and the durability of our SPR-based optical touch sensor. Other key features include ease of implementation, prevention of a light beam becoming incident on the user, and the ability to accept both strong and weak activating forces.

© 2006 Optical Society of America

Full Article  |  PDF Article
More Like This
Optical multilayers for LED-based surface plasmon resonance sensors

Radan Slavík and Jiří Homola
Appl. Opt. 45(16) 3752-3759 (2006)

High-sensitivity small-angle sensor based on surface plasmon resonance technology and heterodyne interferometry

Shinn-Fwu Wang, Ming-Hung Chiu, Chih-Wen Lai, and Rong-Seng Chang
Appl. Opt. 45(26) 6702-6707 (2006)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (5)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (2)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved