Low Temperature Photoacoustic Spectroscopy Detection System Developed

Photoacoustic spectroscopy is by measuring the thermal properties of samples, and the achievement spectrum measurement technique . It determines the heat of the sample by measuring samples in contact with the coupling pieces of the volume and changes of pressure. This technology has characteristics of high sensitivity, strong Pervasive, and particularly suited to testing strong scattering, non-transparent sample.It has been widely applied in biomedical, physical, chemical and environmental monitoring, and other fields. Basing on the basic theories of the condensed-ray spectroscopy techniques we design stable performance, high sensitivity optical spectroscopy detection system which can work at liquid nitrogen temperature, and use high power xenon lamp as a light source, and in conjunction with the monochromator used in the scanning area 300nm-800nm, and And to take into fiber technology, optimization of the optical design for the sound to enhance the optical sound footing, Photo acoustic made by the photo acoustic cell measured optical signal is send directly into t lock-in amplifier and can be detected without preamplifier. This Improve the photo acoustic cell sensitivity and the signal-to-noise ratio. By experimental system through different equipment and computer communication interface, we program to enable the system to precise synchronization of the system to achieve the control and signal acquisition, Test data processing in a computer-controlled automatic with using VB language.At the end of paper, the system of photo acoustic spectrometer is proved by experiment. including the use of the system measured at room temperature and liquid nitrogen temperature chopped-and-frequency acoustic signal; test chopped-and-frequency acoustic signal; experimental system power spectrum measurement; at room temperature and liquid nitrogen temperature Gd-Ba-Cu-O thin film photo acoustic spectroscopy measurements.