Enhanced light-target interaction using a novel anti-resonant waveguide concept

Oliver Schmidt; Michael Bassler; Peter Kiesel; Oliver Wolst; Gottfried H. Döhler

doi:10.1117/12.648245

27 February 2006 Enhanced light-target interaction using a novel anti-resonant waveguide concept

Oliver Schmidt, Michael Bassler, Peter Kiesel, Oliver Wolst, Gottfried H. Döhler

Proceedings Volume 6094, Optical Diagnostics and Sensing VI; 60940F (2006) https://doi.org/10.1117/12.648245
Event: SPIE BiOS, 2006, San Jose, California, United States

Abstract

In optical biosensors waveguides are a good choice to deliver light to the area used for sensing. In traditional optical waveguides the light is confined by total internal reflection inside of a high index layer surrounded by regions of low refractive index. Since many sensing applications are based on liquids, it is necessary to guide the light within the liquid. Liquids usually have a lower refractive index than their surroundings. Hence, conventional waveguides provide only a weak interaction between light and target molecules. In order to improve the interaction we are using a novel anti-resonant waveguide concept, in which the core region has a lower refractive index than the cladding layers. With this concept the light can be guided within the target-containing medium, thereby enabling an extended interaction length. An anti-resonant waveguide is especially compatible with a fluidic biosensor because the fluidic channel itself can be used as the core of the anti-resonant waveguide. The light propagation and coupling mechanism of an anti-resonant waveguide is reviewed and is demonstrated with large area fluorescence excitation. By coupling the excitation light into a liquid film between two glass slides we are able to excite fluorescence within a 5 cm long channel. The measured fluorescence intensity per unit area is equal to that obtained by focusing the total excitation power onto a small spot. From analyzing the angular intensity distribution at the end facet of the waveguide we gain a better understanding of the guiding mechanism.

Citation Download Citation

Oliver Schmidt, Michael Bassler, Peter Kiesel, Oliver Wolst, and Gottfried H. Döhler "Enhanced light-target interaction using a novel anti-resonant waveguide concept", Proc. SPIE 6094, Optical Diagnostics and Sensing VI, 60940F (27 February 2006); https://doi.org/10.1117/12.648245

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available