Dual-Comb, Hyperspectral Nanoscopy of Biological Compounds at the Shot-Noise Limit

Over the past 10 years, near-field based nano-spectroscopy has emerged as a powerful technique for nano-scale chemical identification applicable to a wide range of molecular and biological systems, including polymers, bio-membranes, biofilms, tissues, biominerals, biofuels, and emerging quantum materials. Despite its widespread and growing use in analytical laboratories across industry, academia, and national laboratories worldwide, the lack of a robust, broadband, and cost-effective bright mid-infrared light sources has remained a major constraint. Here, our proposed development and implementation of a mid-infrared frequency comb capable of quantum, shot-noise limited photodetection will vastly improve sensitivity, multi-spectral/multi-compound detection, and spatio-spectral acquisition speed for chemical nano-infrared imaging with applications including the imaging of bio-molecular compounds at the sub-cellular level. The problem of immature and unreliable mid-infrared laser sources is being directly addressed by the extending existing near-infrared laser sources into the mid-infrared region. Additionally, the detection of these laser systems is critical in these applications and will also be addressed to ensure high performance measurements can be acquired. The overall approach of this effort is to utilize as many telecommunications components (due to their robustness) to generate a reliable, easy-to-use, and cost-effective solution for ultrafast mid-infrared research applications. Requirements for a mid-infrared laser system will be finalized after consultation with government, academic, and commercial partners. A compact and robust, broadband mid-infrared (MIR) dual frequency comb spectrometer will be built and tested for enhanced IR-vibrational nano-imaging and nano-spectroscopy at the quantum, shot-noise limit.