Laser Direct Writing of Single-Mode Polysiloxane Optical Waveguides and Devices

• Published in: Journal of lightwave technology Vol. 32; no. 17; pp. 3036 - 3042
• Main Authors: Zgraggen, Eugen, Soganci, Ibrahim Murat, Horst, Folkert, La Porta, Antonio, Dangel, Roger, Offrein, Bert Jan, Snow, Steven A., Young, Jeanette K., Swatowski, Brandon W., Amb, Chad M., Scholder, Olivier, Broennimann, Rolf, Sennhauser, Urs, Bona, Gian-Luca
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Couplings; Laser beams; Materials; Optical device fabrication; Optical waveguides; Waveguide lasers; Writing; single-mode polymer waveguides; Laser direct writing; siloxane; optical interconnects
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2014.2337013

Using a custom-built laser direct writing system, single-mode polymer optical waveguides, and devices for board-level optical interconnects were fabricated. A novel photopatternable polysiloxane material was developed that combines low-loss, simple, and large-area processability, and reliability during manufacturing and system operation. The polysiloxane waveguides were designed with quadratic cross sections of 5.5 × 5.5 μm 2 and a refractive index contrast of 0.0086 between core and cladding polymer for single-mode operation at the wavelength of 1.3 μm. A straight waveguide propagation loss of 0.28 dB/cm was achieved. A wide range of passive optical devices, including Y-splitters, directional couplers, and Mach-Zehnder interferometers were successfully fabricated and characterized. The results prove that the presented combination of material and process technology is a viable implementation for short distance board-level optical links.