Thermal nanoimprint lithography (NIL) is presented as an alternative fabrication technique for patterning deoxyribonucleic acid (DNA) biopolymer films for photonic device applications. The techniques and procedures developed for directly imprinting optical waveguide structures on a DNA biopolymer using NIL, bypassing the use of a resist layer and any chemical processing, are outlined here. The fabrication technique was developed with a Nanonex NX-2600 NIL flexible membrane system. Additionally, a process for using a Suss MicroTec ELAN CB6L substrate bonder is discussed as an alternative to commercially available NIL systems.
A polymer electro-optic (EO) waveguide beam-steering device with deoxyribonucleic acid (DNA) biopolymer conductive cladding layers and a core layer of the commercially available EO polymer SEO100 is demonstrated with 100% relative poling efficiency. This demonstration device exhibits a deflection efficiency of 99 mrad/kV with a corresponding in-device EO coefficient r33 of 124 pm/V at 1550 nm. When the DNA biopolymer bottom cladding layer is replaced by the commonly used cladding polymer UV15, the deflection efficiency and in-device r33 drop to 34 mrad/kV and 43 pm/V, respectively.
In this paper we present our current research in exploring a DNA biopolymer for photonics applications. A new
processing technique has been adopted that employs a modified soxhlet-dialysis (SD) rinsing technique to completely
remove excess ionic contaminants from the DNA biopolymer, resulting in a material with greater mechanical stability
and enhanced performance reproducibility. This newly processed material has been shown to be an excellent material
for cladding layers in poled polymer electro-optic (EO) waveguide modulator applications. Thin film poling results are
reported for materials using the DNA biopolymer as a cladding layer, as are results for beam steering devices also using
the DNA biopolymer. Finally, progress on fabrication of a Mach Zehnder EO modulator with DNA biopolymer
claddings using nanoimprint lithography techniques is reported.