Study On Modulating Stability Of Laser Wavelength Realized By Acetylene

Laser technology is an emerging science developed from the early 1960s, laser frequency is stable or not will directly affect the measurement accuracy and the quality of reception. Therefore, to control and restrain the fluctuations of laser frequency has become an important branch of the laser application technology. In this paper, a frequency stabilization system based on acetylene absorption method is designed and studied, theories and experiments both prove that its frequency stability is significantly reformed. The primary content includes:Firstly, the principles and methods of laser frequency stabilization are studied, the space mode structure and spectrum are expatiated, and the relationship between the gain coefficient and the output power is analyzed, the definition of frequency stability and repletion are present, then the methods how to measure frequency stability are introduced, and the factors affect the laser frequency stabilization are analyzed. Several common laser frequency stabilization methods are introduced and make some simple comparisons. Then the molecule saturated absorption frequency stabilization principles are importantly analyzed, in the end the width and lines of spectrum and how to choose the absorption medium are also analyzed.Thereafter, a complete laser frequency stabilization system is designed, acetylene gas is selected as the absorption medium, the saturated absorption frequency stabilization method is used to make the frequency stable, and its frequency stabilization principle is detailed expounded. The work principles of FBG external cavity semiconductor laser and how to use optical fiber grating to realize mode spectrum choice, then the parameters of FBG external cavity semiconductor laser in the system are derived from the formula calculation. An absorption gas cell that fitted this system is designed by comparing several typical absorption gas cells and according to the principles of the absorption gas cell design. How to connect and couple various parts of fiber in the system is analyzed, and the work principle, indicator requirements, and performance parameters of the detection device that used in system are expatiated.At last, the experimental research of the laser frequency stabilization system is detailed introduced. The factors that affect stability of FBG external cavity semiconductor laser are analyzed and some simulation analyses are done. The fiber optical route loss in the system is analyzed and the result of test is given out. Meanwhile the frequency stabilization system is adjusted and the frequency spectrums before and after frequency stabilized are compared. The experimental results are discussed, and then the reasons for errors are analyzed.