Design,Fabrication,Calibration And Ground-Based Observational Applications Of Monolithic Field-widened Spatial Heterodyne Interferometer

Monolithic spatial heterodyne interferometer has significant advantages in space borne remote sensing scientific applications.It can provides large resolving power and high throughput with compact volume,and the monolithic structure with no moving part makes it extremely robust.As a study of the kernel of this technique,we designed and fabricated 1-D and 2-D monolithic special heterodyne interferometers for 940nm water vapor absorption band with commercial optical elements and conventional laboratory conditions.Calibrations and experiments show that their performances were steadily near the design predictions.We set up a ground-based 940nm water vapor absorption band observe system with the 2-D interferometer,the observed result matched very well with simulation.The main contents of this thesis are summarized as follow:1.Firstly,we introduce the research status of spatial heterodyne spectroscopy(SHS),the scientific applications of SHS are classified by the use as emission/absorption spectrum passive measurement SHS,Raman spectrum active measurement SHS and Doppler SHS.2.The optical principles of 1-D and 2-D spatial heterodyne interferometers are described next,which include the relationship between the input spectrum and frequency domain of the interferogram,and the determinants of spectral resolution and spectral range.There is also an introduction about field widen theory of SHS,and the design formulas of the field widening prisms parameters are given.These together give us a theoretical basis of designing a monolithic field widened spatial heterodyne interferometer based on the practical use.We also give a brief introduction of Doppler asymmetric spatial heterodyne interferometer for atmospheric wind speed.3.As a practice,we have designed 1-D and 2-D monolithic field widened SHS interferometers to observe the direct solar-irradiance spectrum around 940nm water vapor absorption band.In order to fabricate the monolithic interferometers,we build a breadboard of SHS system.The monolithic interferometers are aligned and cemented on the breadboard under the condition of monitoring the interferograms and corresponding 2-D Fourier transforms for known calibration light source.We have tested the fabricated monolithic interferometers with uniform monochromatic extended source,the fringe visibility of the fabricated 1-D and 2-D interferometers are respectively-0.73 and-0.41,which indicate a good performance of interference efficiency.4.1-D interferometer is suitable for the situation that spectrum varies along vertical direction such as atmosphere limb.We simulate the situation with traditional neon lamp and assembled anamorphic telescope and test the 1-D interferometer with it,the result is identical with prediction,and the parameters are close to the design.For the convenience of ground-based observation,we build an integrated SHS system with the assembled 2-D interferometer.The SHS system is thoroughly calibrated with tunable laser,wavelength meter and power meter,the calibration results are necessary for interferogram data inversion.We've also calculate the phase distortion with the calibration data,which can be used to correct the phase error of original interferogram.5.Finally,the SHS system is coupled to a precise adjusted equatorial telescope via a fiber to observe the direct solar-irradiance spectra around 940nm water absorption band at our atmospheric observation site.The observed solar spectra matched very well with corresponding results simulated using MODTRAN in both dry season and wet season.We infer the water vapor column abundance by calculating the correlation coefficient between ground-based observed solar spectrum and simulated spectrum by MODTRAN with different water vapor column abundance inputs,the result has a same variation trend with water vapor column abundance below 10km measured by microwave radiometer.