Mode-hop-free Tuning Of External Cavity Laser Based On Grating Phase Shift Effect

The Semiconductor Diode Laser(LD)has been widely used in various fields since its invention in 1962.The appearance of wavelength-tunable semiconductor lasers has expanded the application of semiconductor lasers to high-precision measurement and holographic data storage.Laser cooling and other high-tech fields.As an tunable wavelength semiconductor laser,an external cavity semiconductor diode laser(ECSDL)uses an external cavity structure composed of an optical feedback device to achieve wavelength tuning,which is a further reduction of the line width compared to a common semiconductor laser.Wide,enhances the tunability of the wavelength while increasing the single mode performance of the laser output.The main contents and research results are as follows:1.Introduced the development process of LD and two main structures of grating ECSDL: littrow and littman;introduced the structure and principle of F-P cavity,which is also an important part of the laser.2.Explained what is the phase shift effect of the grating,theoretically analyzed how the phase shift effect of the grating affects the tuning of the wavelength,and designed the experiment scheme to use the phase shift effect of the grating to realize the wavelength-free mode-free continuous tuning of the grating ECSDL.3.In the thesis,Littrow and Littman two kinds of grating ECSDL were used to carry out the wavelength-free mode-free continuous tuning range of the measurement experiment and obtained their own experimental data,and improved the experimental method to expand the scope of its non-hop mode tuning.The final experiment achieved a mode-free continuous tuning of the Littrow type ECSDL with a range up to 10.5 GHz;the Littman-type ECSDL has a mode-free continuous tuning range of 3.5 GHz.4.In the course of experiments using Littrow and Littman ECSDL,it was found that the frequency change rate of the two in the wavelength tuning process is not the same.After theoretical analysis and calculation,the frequency change rate of the two is obtained under the same experimental conditions.The rate of change of the Littman outer cavity structure is twice that of the Littrow outer cavity structure,and experimental calculations have verified the theoretical calculation results.