Enhancing sensitivity in absorption spectroscopy using a scattering cavity

Abstract

Absorption spectroscopy is widely used to detect samples with spectral specificity. Here, we propose and demonstrate a method for enhancing the sensitivity of absorption spectroscopy. Exploiting multiple light scattering generated by a boron nitride (h-BN) scattering cavity, the optical path lengths of light inside a diffusive reflective cavity are significantly increased, resulting in more than ten times enhancement of sensitivity in absorption spectroscopy. We demonstrate highly sensitive spectral measurements of low concentrations of malachite green and crystal violet aqueous solutions. Because this method only requires the addition of a scattering cavity to existing absorption spectroscopy, it is expected to enable immediate and widespread applications in various fields, from analytical chemistry to environmental sciences.

High-Dynamic-Range Absorption Spectroscopy by Generating a Wide Path-Length Distribution with Scatterers

“…As demonstrated in previous studies, many of these approaches aim to alleviate the problems of light scattering and replicate the effects observed in an integrating sphere [34][35][36], as well as to enhance the sensitivity of absorption spectroscopy. In particular, the latter is achieved through a method known as multiscattering-enhanced absorption spectroscopy (MEAS), which involves dispersing gold nanoparticles in the sample solution [37] or surrounding the sample with a scattering cavity [38] to increase the PL and thereby enhance detection sensitivity.…”

Rapid Bacterial Detection in Urine Using Laser Scattering and Deep Learning Analysis

“…The use of multiple light scattering to enhance optical signals has been utilized to overcome the sensitivity limitations of conventional optical devices ( 18 ), including scattering super lenses ( 19 ), temperature sensors ( 20 ), pressure sensors ( 21 ), wavelength meters ( 22 ), fiber-based spectrometers ( 23 ), absorption spectrometers ( 24 ), and nonresonant lasers ( 25 ).…”

Compact nano-void spectrometer based on a stable engineered scattering system

“…Wavemeters based on an integrating sphere have been used to demonstrate sub-femtometer resolution [7,8], yet size and stability requirements limit applications to specialist and laboratory settings. Since 2013, a compact spectrometer chip based on a silicon-on-insulator scattering medium has been utilised to increase the optical path length and enable better spectral resolution within the same physical space [9,10]. The first version of such a device was designed as a two-dimensional random air holes etched into the silicon plane [3].…”