Diode-Laser Based Spectroscopy Measurement System

Due to the rapid development and continual progress of the diode laser, it's more and more used in the front side of science research like high resolution spectroscopy, laser cooling and atom captivity, new quantum frequency standard, etc.In this thesis, we demonstrated a spectroscopy measurement system including wavelength measurement unit, signal detecting and data acquisition units based on the DL10 diode laser system made by Topica Photonics Corp. in Germany.First, the principle of the DL100 laser and how to made hop free scans with it were introduced. Some important parameters got from experiments but not included in the laser manual were also presented.And, to get correct wavelength data, Burleigh WA-4500 wavelength meter was used. With the efforts on hardware connection and software programming, the data was transported from WA-4500 to the main control computer through RS232 serial communication.Then, in the experiment, velocity modulation was combined with auto-balanced differential detection technique to get really good results. Auto-balanced differential technique was also used in the I₂ hot-band absorption spectrum for absolute wavelength adjustment and its characteristics for application were discussed.After that, an ISA DAQ card was used to control the scan of the laser and record the spectrum data. With really easy manipulation and friendly interface, the automation of the measurement was realized.Last, the whole experiment system was tested and got satisfied results.