Research On High Spectral Resolution Spatial Heterodyne Spectrometer For Laser-Induced Breakdown Spectroscopy

Weak spectral signals and spectral overlap are common in the practical application of Laser-Induced Breakdown Spectroscopy(LIBS)due to the numerical aperture and the low resolution of the spectrometer.It is necessary to take rational methods to sepa-rate the overlap peak and to improve the detection sensitivity which will be helpful to enhance the accuracy of qualitative and quantitative analysis of the object under test.We often limit the width of the slit to guarantee the adequate spectral resolution in cur-rently used spectrometer,however,this also reduces the throughput of the spectrometer which results in a decline in the sensitivity of the detection signal.Spatial heterodyne spectrometer(SHS),which is based on Fourier transform spectroscopy of Fizeau inter-ference fringes,has open a brand new avenue for hyper spectral resolution technique.It could be served as a high throughput and high spectral resolution tool for LIBS de-tection because the spectral resolution is not limited by slit.Meanwhile,it also has the merits of broad range coverage,no moving parts,compact size,easily integrated,small volume and power consuming.Spatial heterodyne spectrometer as a kind of high throughput and high resolution spectral technique for LIBS technique has the potential to resolve the overlapped peak and improve the detection sensitivity of spectral signals in the actual detection process.This article focuses on high resolution,high throughput and integrated spatial heterodyne spectrometer techniques,the main contents include:1.With the requirements of high spectral resolution and high throughput LIBS detection as the research background,spatial heterodyne spectrometer was introduced.The applications of spatial heterodyne spectrometer and the trends of miniaturization were summarized.2.The theoretical mechanisms of LIBS and spatial heterodyne spectrometer have been elaborated and demonstrated.Two different data processing methods of spatial heterodyne spectrometer were also briefly described.3.We carried out research on high throughput,high resolution LIBS detection based on spatial heterodyne techniques and broke through the limitation that traditional spectrometers could not obtain high throughput and high resolution at the same time beacause of the slit.High resolution detection system for LIBS applications was built.The wavelength calibration and data processing methods were also described.With the use of Rodrigues,rotation formula,we establish the model of mounting error of optical system and analyze the influence caused by this error.The analysis results provide theoretical guidance for adjustment and assembly.4.For the targets of miniaturization and convenience,a miniature spatial hetero-dyne spectrometer based on wireless image transmission module was developed.It is able to monitor the spectrum from your cell-phone via this integrated system.It signif-icantly improves the ease use of the miniature spatial heterodyne spectrometer without accessing computer and AC power supplies.