Optical System Design Of Compact Static Fourier Spectrometer

Fourier spectrometer can be used to obtain targets spectral image information on the basis of double interference theory.It is widely used in military and civil aspects.The traditional Fourier spectrometer has a complex drive structure,which not only limits the stability of the instrument,but also increases the overall volume of the instrument.These factors seriously affect the application range of Fourier spectrometer.Therefore,it is of great significance to study the miniaturization and portable Fourier spectrometer.Static double beam interference theory is adopted in the static Fourier spectrometer,which avoids the use of driving structure and can effectively reduce the volume of the system.At present,the study of Static Fourier spectrometer is mainly focused on the improving of measurement accuracy and structure designing of beam splitter,which limits the performance improvement of Static Fourier spectrometer.In this paper,a compact static Fourier spectrometer optical system is designed based on the double right-angle beam splitter.In this paper,a theoretical study is carried out based on the theory of Fourier spectrum.Firstly,the advantages and disadvantages of several typical beam splitter structures are discussed and the structure of the splitter consisting of two right angle trapezoid is mainly studied.Then a compact optical system with static Fourier spectrometer is designed.Last,the spectral experiments are carried out by using the mercury lamp and laser light source through the prototype and interference diagram spectral images obtained in the experiment can be used as image retrieval to recovery its original spectrum.The main research contents and results are as follows:(1)A compact static Fourier spectrometer of optical system is designed,which includes pre-optical system designing and double right angle(orthogonal angle)beam splitter optical system designing.The advantages and disadvantages of several typical transverse shearing beam splitter structures are compared and the performance parameters of the double right-angle beam splitter are calculated.It is obtained bycalculation that the vertical height of the optical path can be reduced to 24 mm when the inclination angle of the spherical mirror and the cylindrical mirror is 6 in the rear optical structure.(2)In the process of designing,ZEMAX software is used to optimize and simulate the optical system after initial spectrometer structure parameters calculated,achieving a high spectral resolution of 2.17 nm at wavelength 400 nm,which is consistent with the theoretical calculation.Under certain conditions,the interference fringes system is independent of the size of the slit.Above results indicate that the compact static Fourier spectrometer optical system satisfies the design requirements.(3)The installation of the optical system prototype of the static Fourier spectrometer is completed and related spectrum test experiments on this basis is carried out.The interference data obtained is processed,including data preprocessing,profile,Fourier transform and so on.The mercury lamp characteristic spectrum of404.4nm ?436.1nm ?545.8nm and 577.2nm is obtained by using the mercury lamp as the calibrated light source,and the recovery spectrum is in good agreement with the actual spectrum.In addition,the spectral resolution is about 5.93 nm by using the single wavelength laser of 650 nm to conduct spectral resolution experiments.Above experimental results are consistent with the theory.In conclusion,the proposal optical system design in this paper is feasible and effective.The spectrometer optical system,which is based on a double right-angle beam splitter and combined with a tilted spherical mirror and a cylindrical mirror,provides technical support for the realization of a light and small Fourier spectrometer with a stable structure,small size and high precision.