Transferable Integrated Optical SU8 Devices: From Micronic Waveguides to 1D-Nanostructures

International audienceWe report on optical components for integrated optics applications at the micro-and nanoscale. Versatile shapes and dimensions are achievable due to the liquid phase processability of SU8 resist. On the one hand, by adjusting the UV-lithography process, waveguiding structures are patterned and released from their original substrate. They can be replaced on any other substrate and also immerged in liquid wherein they still show off efficient light confinement. On the other hand, filled and hollow 1D-nanostructures are achievable by the wetting template method. By exploiting the large range of available SU8 viscosities, nanowires of diameter ranging between 50 nm and 240 nm, as well as nanotubes of controllable wall thickness are presented. Optical injection, propagation, and coupling in such nanostructures are relevant for highly integrated devices

Micro-fabrication of a Mach-Zehnder interferometer combining laser direct writing and fountain pen micropatterning for chemical/biological sensing applications.

This research lays the foundation of a highly simplified maskless micro-fabrication technique which involves incorporation of laser direct writing technique combined with fountain pen based micro-patterning method to fabricate polymer-based Mach-Zehnder interferometer sensor arrays' prototype for chemical/biological sensing applications. The research provides methodology that focuses on maskless technology, allowing the definition and modification of geometric patterns through the programming of computer software, in contrast to the conventional mask-based photolithographic approach, in which a photomask must be produced before the device is fabricated. The finished waveguide sensors are evaluated on the basis of their performance as general interferometers. The waveguide developed using the fountain pen-based micro-patterning system is compared with the waveguide developed using the current technique of spin coating method for patterning of upper cladding of the waveguide. The resulting output power profile of the waveguides is generated to confirm their functionality as general interferometers. The results obtained are used to confirm the functionality of the simplified micro-fabrication technique for fabricating integrated optical polymer-based sensors and sensor arrays for chemical/biological sensing applications

JNOG 33 - 2013

National audienceRecueil JNOG 3

Conception of optical integrated circuits on polymers

International audienceThe authors present a successful design, realisation and characterisation of single-mode TE00–TM00 rib optical waveguides composed of SU-8 polymer. For the simulation, a generic software package that provides an interactive and graphical environment for analysis by polarised Semi-Vectorial Finite Difference (SVFD) method of all kinds of integrated optical waveguides, such as buried channel, raised strip, rib, embedded, or ridge waveguides, has been implemented and tested. In this method we have taken into account the terms due to the interface between each layer. After realisation of various single mode optical waveguides on SU-8 polymer and Spin on Glass (SOG) like straight, S-bends, Y-junctions, Mach-Zehnder (MZ) interferometers, the linear absorption coefficient of energy αTE–TM of such rib waveguides have been measured and estimated, respectively, near 0.32 and 0.46 cm−1 for both optical modes TE00 and TM00 on Si/SiO2/SU-8 structures. These values yield optical losses of 1.36 and 2.01 dB/cm. Optical losses ascribed to Si/SiO2/SOG/SU-8 microstructures have been evaluated to 2.33 and 2.95 dB/cm for both polarisations. Hence, as a crucial step for designing polymer components devoted to microsensors applications (pressure, heat transfert), the SU-8 polymer appears as a promising candidate for integrated optics with low optical losse