Archive | 2019
Combined Application of SRS and Photoacoustic Imaging in Vivo Leaf Tissue in Situ Detection System
Abstract
Absorption and scattering are two common methods to characterize the physical and chemical properties of substances. However, the combined application of the two techniques in situ detection is difficult. Taking biological tissues as an example, proteins and pigments absorb visible light strongly, and the scattering characteristics of soft tissues are obvious. Absorption and scattering can be used to characterize the physical and chemical properties of substances. Scattering characteristics of tissues can reveal information such as cell structure, and the absorption characteristics of tissues can often reflect information such as cell metabolism. The combination of light scattering and photoacoustic effect can extract all kinds of physical and chemical information of tissue and molecule at the same time and detect them in situ. Due to the influence of the detected objects, the combined application of the two in situ detection techniques is difficult. Therefore, in order to compensate for each other s shortcomings, the photoacoustic effect caused by optical absorption and Raman scattering are used to detect living tissues, and a combined experimental system of Raman and photoacoustic imaging in situ detection is proposed. Raman and photoacoustic signals are synchronously stimulated by high repetition frequency pulsed laser and multiplexed by optical system. On the basis of experiments of adjusting repetition frequency and power of pulsed laser, the effects of parameters of pulsed laser on Raman and photoacoustic signals are analyzed. The results are of great significance for analyzing optical and acoustic signals of living tissues. Introduction Active photoelectric detection technology is the main means to study the influence of space environment on the life of higher plants on the earth and to analyze the mechanism of physiological changes. According to the requirements and objectives of the roadmap planning for the space life sciences experiment proposal of the Chinese Space Station from 2020 to 2032, and in view of the planned requirements of basic research in the fields of gravity biology and radiation biology of higher plants , the active detection technology scheme for cell and molecular level research of higher green plants is proposed and verified[1-2]. In this paper, photoacoustic and spectral imaging observations are used to characterize the effects and mechanisms of biological physiological homeostasis, providing basic research data for solving basic biological problems such as survival and adaptation of earth organisms in special environments. The strategic needs of China s future space life science include basic research and exploration of space basic biology and cosmobiology supported by manned space activities . Relevant research in this field includes: phenomena of perception, response and adaptation of earth organisms to space environment; laws of influence of space environment on physiological stability of earth organisms; and exploration of origin, evolution and distribution of life in the universe[2-3]. In this paper, an active detection technology combining laser spectroscopy with photoacoustic effect is proposed. The technology includes Stokes Raman Scattering (SRS) and Photoacoustic Microscopy (PAM) caused by photoacoustic effect, in which SRS is the result of radiation transition caused by absorption of external energy by molecules, PAM is the result of non-radiative transition when molecules absorb external energy, at which time energy propagates in the form of heat energy. 2nd International Conference on Electrical and Electronic Engineering (EEE 2019) Copyright © 2019, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Engineering Research, volume 185