Enhanced sensing performance from trapezoidal metallic gratings fabricated by laser interference lithography

• DOI: 10.1364/ol.450151
• Publication Date: 2022-01-14T17:52:13Z
• Authors: Yuwei Chai; Fangfang Li; Junyi Wang; Petri Karvinen; Markku Kuittinen; Guoguo Kang
• Keywords: Interference lithography; Figure of Merit

Nanograting-based plasmonic sensors are widely regarded as promising platforms due to their real-time label-free detection and ease of integration. However, many reported grating structures too complicated fabricate, which limits application. We propose a 1D bilayer metallic with trapezoidal profile near-infrared sensor in the spectral interrogation. Trapezoidal gratings tend perform better than rectangular sensors, particularly they can detect at oblique incidence obtain higher performance. Furthermore, we have successfully fabricated such period 633 nm over 2.25 cm2 area using two-step approach based on laser interference lithography. Glucose has been conducted experimentally validate sensing performance as-prepared grating. The measured sensitivity figure-of-merit reach up 786 nm/RIU 30, respectively. Our research sheds new light development cost-effective devices.