Nonlinear Brillouin spectroscopy: what makes it a better tool for biological viscoelastic measurements

Abstract

Brillouin spectroscopy is an emerging tool in biomedical imaging and sensing. It is capable of assessing the high-frequency viscoelastic longitudinal modulus with microscopic spatial resolution. Nonlinear Brillouin spectroscopy based on impulsive stimulated Brillouin scattering offers a number of significant advantages over conventional spontaneous and stimulated Brillouin scattering. In this report, we evaluate the accuracy of Brillouin shift measurements in spontaneous and nonlinear Brillouin microscopy by calculating the Allan variance for both CW excited spontaneous Brillouin measurements and nonlinear Brillouin scattering measurements made with both nanosecond and picosecond pulse excitation. We find that impulsive stimulated Brillouin spectroscopy is superior to spontaneous Brillouin spectroscopy in terms of the accuracy of such measurements and demonstrate its application for assessing tiny changes in Brillouin frequency shifts associated with low concentrations of biologically relevant solutions.

Excitation of Faraday-like body waves in vibrated living earthworms

“…... . E 8 3 8 9 MPa range, which corresponds to the mode = = n m ( 3,3) excited at = f 38 Hz and the mode = = n m ( 2,3) excited at = f 43 Hz. The corresponding values of the frequency factor are shown by the two horizontal lines in Fig.…”

“…Vibrations and fluid-structure interactions are essential for efficient communication between living beings and they also underpin human-made imaging, spectroscopy and sensing techniques such as medical ultrasound and photoacoustic imaging modalities 1 , Brillouin Light Scattering spectroscopy 2 , and laser vibrometry 3 to name a few. Sound and vibrations are also likely to play an important role in the propagation of nerve impulses 4,5 as well as they can be used to develop new methods of bacteria and virus killing [6][7][8] .…”

Mechanical Characterization for Cellular Mechanobiology: Current Trends and Future Prospects

“…Since its pioneering application in 2005 (Koski and Yarger, 2005), Brillouin microscopy has been utilized in tissue-level sensing (Mathieu et al, 2011;Margueritat et al, 2019) and subcellular-level characterization (Steelman et al, 2015;Bevilacqua et al, 2019). However, interpretation of results requires specific knowledge of the refractive index and material density (Prevedel et al, 2019) which is difficult to experimentally attain (Liu et al, 2016), and the weakness of the measured signal causes extended scanning and data acquisition times (Ballmann et al, 2019). Scrutinous evaluation of Brillouin output is also required, especially in biological matter, due to the spatiotemporal inhomogeneity causing differences in the material's intrinsic acoustic wave behavior (Wu et al, 2018;Ballmann et al, 2019).…”

Stimulated Brillouin gain spectroscopy in a confined spatio-temporal domain (30 μm, 170 ns)

“…Quite recently, the use of virtual image phase array spectrometers [12] has greatly increased the acquisition time of the spontaneous spectra allowing among other things to obtain Brillouin spectra of in vivo biological tissues [13]. Reference [14] is a recent review on Brillouin spectroscopy for biological issues, including a discussion of the possible advantages of SBG spectroscopy on spontaneous Brillouin spectroscopy, also discussed in reference [15].…”