Research On Echelle Parameters Detection System

Echelle,which is highly appreciated due to its excellent properties in recent years,has the advantages of low groove density,wide blaze angle,high diffraction grades,wide spectral range,high dispersion ratio,high spectral resolution among others.Using echelle as the main dispersion spectrum instrument called the echelle spectrograph,Echelle spectrograph is a high-end spectrum analysis instrument,has the advantages of small volume,high resolution,high dispersion rate,and full spectrum direct reading,has become the representative of advanced spectrum instrument with a broad application prospect.Diffraction efficiency and stray light coefficient which can express the quality of the echelle directly reflect the optical properties of the echelle,Thus,accurate measuring of the diffraction efficiency and stray light coefficient is the precondition for grating applications.Therefore,with the support of the National Major Scientific Instruments and Equipment Development Projects,the paper carried on the following research,Firstly,comparing with different typical grating diffraction efficiency and the stray light measurement method,According to the property and characteristics of the echelle,design a detection system which can be used for measuring the echelle diffraction efficiency and stray light.The system consists of light source,front monochromater,measurement monochromater,observe and control system.The front monochromater uses a symmetrical C-T structure to provide monochromatic light of the wavelength range from 200 nm to 2500 nm with a spectral resolution better than 0.2nm and up to 0.1nm,can provide stable and reliable monochromatic light source for the detection system.the detection system can be used to measure echelle diffraction efficiency with the spectral range from 190 nm to 1100 nm,and the system can also be used to measure echelle stray light with the spectral range from 200 nm to 800 nm,spectral resolution better than 0.2nm.Secondly,the front monochromater and the whole optical system are simulated with optical design software CODE V,giving the aberration curve and column points in different spectral range.Thirdly,according to the structural parameters of the system,building the principle prototype and verified by experiment.Measuring diffraction efficiency and stray light of the echelle,analyzing the measurement results,and comparing with the theoretical values to analyze the performance of the detection system.