Device Integration Using 3D Printed Glass Micro-Optics

The integration of micro-scale optical systems for use as sensors, medical devices and photonic platforms is challenging using typical assembly practices that often result in low efficiency light coupling (&lt;10%). The ability to 3D print micro-optics directly onto light sources, fibers, detectors, photonic integrated circuits, etc., could drastically simplify design, iteration and implementation of advanced optical systems. Using a free-from design approach such as multiphoton lithography (MPL) affords the ability for print-on polymer optics with nano/micro scale resolution. Moreover, recent work showing MPL fabrication of silica glass processed under low temperature provides a possible route for direct integration of mechanically robust, environmentally rugged optical grade materials. The use of molecular/polymeric materials (polyhedral oligomeric silsesquioxanes, POSS; polydimethylsiloxane; PDMS) versus nano-silica precursors used previously [1], enables printed forms to be processed into silica glass at relatively low temperatures (&lt;650C; [2]) or using deep-UV/ozone approaches (~220C; [3]). Here, we investigate 3D printed glass micro-optics for chip to fiber connections by quantifying design fidelity, shrinkage, surface roughness and coupling efficiency of microlenses printed using standard layer-by-layer MPL as well the dynamic voxel approach (two-photon grayscale lithography; 2GL[4]). We investigate incorporation of POSS derivatives (such as octa(dimethylsiloxy) silsesquioxane) to increase initial SiO₂content and decrease shrinkage upon thermal decomposition. Finally, we fabricate a multi-lens optic for fiber/detector connection and demonstrate high efficiency coupling (&gt;10%) using an all-glass integrated assembly. This ability to make mechanically robust and accurately aligned glass micro-optical assemblies promises to revolutionize the design and performance of advanced optical systems.<br/><br/>[1] <i>Nature</i> 544, no. 7650 (2017): 337-339.<br/>[2] <i>Science</i> 380, no. 6648 (2023): 960-966.<br/>[3] <i>Science Advances</i> 9, no. 40 (2023): eadi2958.<br/>[4] nanoscribe.com/en/microfabrication-technologies/2gl-two-photon-grayscale-lithography