Abstract
Abstract Raman identification is an instrumental tool with a broad range of applications, yet current spectroscopy approaches fall short in facilitating practical and scalable Raman identification platforms. In this work, we introduce a spectrometerless Raman identification approach that utilizes guided-mode resonance filters. Unlike arrayed narrowband-filters spectrometer, we tailor the transmission characteristics of each filter to match the Raman signature of a given target. Hence, instantaneous Raman identification could be directly achieved at the hardware level with no spectral data post-processing. The filters consist of a metasurface grating encapsulated between two identical distributed Bragg reflectors and are characterized by transmission peaks line-widths narrower than 0.01 nm and transmission efficiency exceeding 98%. We develop a rigorous design methodology to customize the filters’ characteristics such that the maximum optical transmission through a given filter is only attained when exposed to the Raman scattering from its matched target. To illustrate the potential of our approach, we theoretically investigate the identification of four different saccharides as well as the classification of two antibiotic-susceptible and resistant strains of Staphylococcus aureus. We show that our proposed approach can accurately identify these targets. Our work lays the foundation for a new-generation of scalable, compact, and cost-effective instant Raman identification platforms that can be adopted in countless applications from wearables and point-of-care diagnostics to in-line quality control in food and pharmaceutical industries.
Highlights
Since the first observation of Raman scattering in 1928 [1], it has emerged as one of the most intriguing light–matter interaction phenomena
The transmitted intensity spectra around peak (I) of the MSSA2 and peak (II) of the MRSA2 are shown in classification of resistant and susceptible S. aureus can be accurately achieved through direct Raman imaging with our spectrometerless approach
By leveraging subwavelength metasurface gratings, we have shown that the filter transmission characteristics can be tailored for specific Raman signatures without compromising the transmission efficiency
Summary
Since the first observation of Raman scattering in 1928 [1], it has emerged as one of the most intriguing light–matter interaction phenomena. Mousa et al.: Toward spectrometerless instant Raman identification (>1 nm), narrow operation bandwidth, or inefficient onchip coupling Another promising approach for compact spectrometers utilizes on-chip narrow-band optical filters integrated on photodetector arrays [32,33,34,35,36,37,38,39,40,41]. We can pre-determine the unique features and the particular regions-of-interest in the targeted Raman signatures and only measure the spectral strength at these spectral lines Different areas on the imaging sensor light up depending on the target Successful implementation of this approach requires optical filters with very efficient transmission characteristics and narrow line-width. We theoretically validate this approach in two identification problems; saccharides identification and pathogenic bacteria classification
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
