Photoacoustic experiments of glucose aqueous solution based on pulsed laser induced ultrasonic technique

Abstract

In this work, to further find the characteristic wavelengths of glucose, the photoacoustic experiments of glucose aqueous solutions were performed by using the photoacoustic technique. The photoacoustic detection system was established by the Q switched Nd: YAG OPO pulsed laser and ultrasonic detector with central frequency of 20MHz. The photoacoustic signals of samples were averaged with 512 times. Baed on the established photoacoustic detection system, the time-resolved photoacoustic signals of glucose with different concentrations at the different wavelengths were captured by the digital oscilloscope, and compared with that of the pure water. In order to get the characteristic wavelengths of glucose, the photoacoustic peak-to-peak values of glucose with different concentrations at the wavelength from 1350nm to 2100nm were obtained, and the difference spectral was gotten by using the difference method between the glucose solutions and pure water. Moreover, the first order derivation method was also used. The wavelength of 1650nm and 1850nm was chosen as the characteristic wavelengths of glucose. The linear fitting equation was established to verify the availability of two characteristic wavelengths. The average prediction error results showed that the choosing of the characteristic wavelength of 1650nm and 1850nm is available.