Efficient Processing of Spectral Measurements Using Virtually Imaged Phased Array

The virtual bright fringes method (VBFM) has been here designed to analyze the spectrum signal of Brillouin scattering in water using virtually imaged phased array (VIPA) etalon and an intensified charge-coupled device (ICCD) camera. VBFM is based on the principle of multiple-beam interference with a plane-parallel plate and, thus, only needs the output of the sample to calculate the Brillouin Stokes frequency shift. Moreover, this method substantially reduces the experimental requirements and simplifies the experimental processing. In addition, the capability of this new method has been confirmed by processing experimental data from stimulated Brillouin scattering spectra in water. Our results demonstrated that the experimental results processed by VBFM were in good agreement with the theoretical values. Indeed, VBFM provides a feasible scheme for the measurement of Brillouin Stokes frequency shift with sub-GHz accuracy of 10MHz. VBFM facilitates a broader application of Brillouin scattering, including the measurement of liquid materials and the elastography of biological tissue.