We demonstrate an ultrahigh-sensitive plasmonic sensing of gas, employing a two-dimensional (2D) dielectric grating fabricated by laser interference lithography. The 2D grating was designed with the period of 500 nm and prepared in an AZ1505 photoresist layer on a gold film of 20 nm thickness deposited on a fused silica glass substrate. The surface plasmon resonance (SPR) in the Kretschmann configuration with spectral interrogation was utilized to measure the response of the sensor to vapors of aqueous solution of ethanol. Based on measurement of the gas refractive indices with the reference Au/Cr/SF10 sample, the resonance wavelength dependence was obtained. The SPR response of the structure in a spectral range of 1.68–1.85 µm with a sensitivity of 8200–111,000 nm/RIU was revealed. The sensor provides significantly higher sensitivity in comparison to conventional and grating-based SPR sensors.

In this paper, we present a manual for the preparation of fully functional woodpile structures with partial photonic band gap (PBG) for applications in the visible (VIS) spectral range using an attractive polymer IP-Dip that is novel in photonic applications. In an experimental preparation of polymer-based woodpile structures using the IP-Dip polymer with partial PBG in VIS spectral range, a single-step laser lithography technique based on direct laser writing (DLW) was used. The woodpile structure preparation is based on a complex theoretical analysis of dispersion diagrams for the woodpile structure with fcc symmetry and IP-Dip polymer. We found partial PBGs in the Γ - X direction and dependence of PBG on the filling factor. Using a conventional DLW lithography system, we prepared a series of low-periodic woodpile structures with PBG in NIR and VIS spectral range attacking the yellow-green spectral range, which can be easily applied on different photonic components.