Towards a sensing model using a random laser combined with diffuse reflectance spectroscopy

Area of Science:

• Optics and Photonics
• Biomedical Optics
• Materials Science

Background:

• Random laser emission is influenced by both scattering and absorption properties.
• Random lasers show potential for optical property sensing, but quantitative measurements are limited.
• Existing methods for sensing optical properties in turbid media often lack precision.

Purpose of the Study:

• To develop a generalized mathematical quantitative model for optical sensing in turbid media.
• To integrate random laser technology with diffuse reflectance spectroscopy for enhanced sensing capabilities.
• To establish a reliable method for quantitative measurement of optical properties.

Main Methods:

• A novel quantitative model was developed, separating the gain effect of the active medium and optical properties of the passive medium.
• Rhodamine 6G was used as the active medium.
• Intralipid (scattering) and ink (absorption) were used to validate the model's performance in diverse turbid media.

Main Results:

• The peak wavelength shift of the random laser was identified as an effective sensing parameter.
• The model successfully demonstrated quantitative sensing of scattering and absorption properties.
• Interrelated scaling parameters within the model were simplified to a single parameter.

Conclusions:

• The proposed combined model offers a promising approach for direct quantitative sensing of optical properties in various turbid media.
• This method advances the application of random lasers in optical sensing.
• The findings pave the way for more accurate optical diagnostics and material characterization.