2-Photon Polymerized IP-Dip 3D Photonic Crystals for Mid IR Spectroscopic Applications

Abstract

Photonic Crystals (PhC) are periodically structured dielectric materials that have been subject to extensive research efforts over the last two decades. PhC are known for the slow-light phenomenon, which increases the interaction time between light and the target gas, thereby enhancing sensitivity when applied to sensors. Slow light is best realized using three-dimensional (3D) PhC with a complete photonic band-gap (PBG). However, they are inherently difficult to fabricate with planar microfabrication techniques. In this work, we present two-photon polymerized (2PP) stereolithographically fabricated 3D PhC targeting mid-infrared (MIR) spectroscopic range. Finite Element Analysis (FEA) was performed on a two-dimensional (2D) PhC waveguide (PhCW) to analyze the significance of PBG and slow light properties. Additional FEA was conducted and validated experimentally using fabricated 3D PhC. The ability to tune PhC to a desired wavelength along with their repeatability and feasibility is experimentally demonstrated. This letter presents the first, to our knowledge, 3D PhC fabricated using 2PP stereolithography operating at this wavelength.