Flexible Optical Interconnects via Thiol-ene Two-photon-induced Polymerization

Abstract

Two-photon polymerization (2PP) is an emerging tool in the field of additive manufacturing technologies, which allows for the elegant 3D lithographic production by means of photosensitive resins. One key advantage of 2PP is the achievable feature resolution. A few tens of nanometers are currently the resolution limit for this novel technique. Fields of applications are as diverse as photonics, microfluidics and biomedicine. A challenging photonics application for 2PP are optical interconnects, where optical elements on printed circuit boards are connected with waveguides. The possibility for real 3D structuring allows for easier positioning of the cured structures and straightforward processing outperforming techniques such as 2D lithography or reactive ion etching in this regard. If mechanical flexibility of the printed circuit board is required as a property for certain niche applications, polysiloxanes are an interesting class of matrix material. This is also due to their low optical damping behavior and high temperature stability as the material has to withstand temperatures around 250°C during the manufacturing process. In this work, we present our latest approach to create polysiloxane-based waveguides via 2PP of specially tailored thiol-ene formulations. Latest improvements on the ease of processing and the local refractive index increase are shown as well as the proof of principle for waveguiding. Optical waveguides were successfully created via 2PP with writing speeds around 10 mm/min.

A Low-Bandgap Conjugated Copolymer Based on Porphyrin and Dithienocoronene Diimide with Strong Two-Photon Absorption

“…Thanks to a wide variety of potential applications in microscopy, 1−3 microfabrication, 4,5 three-dimensional datastorage, 6,7 optical limiting, 8 and photodynamic therapy, 9,10 two-photon absorption (2PA) materials have been the subject of intensive academic and commercial interest over the past 2 decades, and a number of 2PA dyes have been synthesized 11−13 and investigated. 14−19 Small molecule based 2PA materials have been investigated extensively, and their 2PA cross sections (δ) are as high as 10 5 GM (1 GM = 1 × 10 −50 cm 4 s −1 ), while the literature on 2PA polymers is significantly sparser than that for their small molecule counterparts, most of 2PA polymers exhibited 2PA cross sections below 10 4 GM.…”