Correction of phase distortion in spatial heterodyne spectroscopy. The development of a high resolution deepuv spatial heterodyne raman spectrometer nirmal lamsal university of south carolina follow this and additional works at. Spatial heterodyne spectroscopy for longwave infrared. The device includes an excitation source and a first spatial heterodyne spectrometer configured to receive wavelengths from the excitation source and filter the wavelengths to produce fringes on a sample.
One of the most promising innovations in the field of raman spectroscopy is the development of the spatial heterodyne raman spectrometer shrs. Us9200961b2 systems and methods for high resolution spatial. Gartley rochester institute of technology, 54 lomb memorial drive, rochester, ny, usa abstract this work presents a radiometric model of a spatial heterodyne spectrometer shs and a. Flat field correction of a spatial heterodyne spectrometer. Pseudomonolithic spatial heterodyne spectrometer interferometer. One of the most promising innovations in the field of raman spectroscopy is the development. A broadband spectral inversion method for spatial heterodyne. Fourier transform spectroscopy, fts 20, arlington, va.
Optical design of an imaging spatial heterodyne infrared. Please use one of the following formats to cite this article in your essay, paper or report. The basic principle of spatial heterodyne spectroscopy is similar to a fouriertransform spectrometer fts in that it also features a beamsplitter which divides the incoming signal into two interferometer arms. The development of a high resolution deepuv spatial. The instrument used the spatial heterodyne spectroscopy technique for the first time on a satellite and successfully demonstrated its.
In particular, we describe spatial heterodyne snapshot imaging interferometers for neutral beam. Development of a highresolution spatial heterodyne libs. Correction of phase distortion in spatial heterodyne spectroscopy christoph r. Development of a spatial heterodyne raman spectrometer. The spectrometer is a modified version of the michelson interfe. Shs permits highresolution, highthroughput measurements. Spatial heterodyne spectroscopy shs employing a twobeam dispersive interferometer producing a fizeau fringe pattern having wavelengthdependent spatial frequencies is presented. A spatial heterodyne spectrometer for laboratory astrophysics. Nathaniel, todd 2011 spatial heterodyne raman spectroscopy doctoral thesis, university of surrey. The opportunities for high redshift observations will be dramatically improved with the launch of the james webb space telescope. Abstract this abstract presents the design and first results of the spatial heterodyne raman instrument shera. Ideal for deepuv laser excitation pure rotational or rovibrational raman measurements planetary landerrover measurements where the wide area collection capability of the instrument allows large areas of the surface to be measured quickly with no loss of. It is well known and demonstrated that interference spectroscopy offers capabilities to obtain passive remote optical sensing spectra of high precision and also achieves economies in size, cost, and ease of deployment compared with more conventional systems. Spatial heterodyne spectroscopy shs is a new instrumental technique for interference spectroscopy which promises to extend into the fuv 12002000 a spectral region the large throughput.
The spectrometer is a modified version of the michelson interferometer in which mirrors are replaced by diffraction gratings. Pdf the use of a spatial heterodyne interferometerbased spectrometer shs for raman spectroscopy is described. One of the main advantages of raman measurements is that the samples need no preparation. An overview of spatial heterodyne spectroscopy cedar. Nrl patent 7,773,229 high quality global thermospheric wind observations are currently not available, but are essential for improving orbit determination and comms. An incoming beam is collimated and passed to the grating in the interferometer where it is split into two beams which are recombined such that the angle between the wavefronts in the recombined beam at a particular wavelength is directly related to the. Spatial heterodyne raman spectroscopy is a spectroscopic detection technique that is particularly suitable for raman measurements. This dissertation will introduce the theories of raman spectroscopy and spatial heterodyne spectroscopy, discuss the use of raman spectroscopy for planetary studies, describe the development of the shrs, and show how the shrs can be used for wide area standoff measurements. Correction of phase distortion in spatial heterodyne. In recent descriptions of this device, one specific phenomenon the tilt of the.
The spectrometer has the configuration of a michelson interferometer but with the mirrors replaced by diffraction gratings fig. Spatial heterodyne spectroscopy shs is a new kind of fouriertransform spectroscopic technique capable of very high spectral resolution. Spatial heterodyne spectroscopy approach to stratospheric wind and ozone measurement. A broadband monolithic spatial heterodyne spectrometer shs system is built for measuring nitrogen. Spatial heterodyne spectrometer shs is a high spectral resolution fourier transform. Raman spectroscopy using a spatial heterodyne spectrometer. Harris, wm 20, allreflective spatial heterodyne spectroscopy. Laserinduced breakdown spectroscopy combined with spatial. Instead of utilizing calibration patterns, the distortion model parameters are estimated based on the distorted fringe features generated by projecting the straight interference stripes onto the detector. Spatial heterodyne spectroscopy shs is a fouriertransform spectroscopic technique with many advantages, such as high throughput, good robustness no moving parts, and high resolving power. The university of south carolina is offering licensing opportunities for this technology. Roesler the detailed analysis of measured interferograms generally requires phase correction. This device is basically a fourier transform spectrometer, but the fourier transform is taken in the directions perpendicular to the optical propagation and heterodyned around one preset wavelength.
An emerging optical technique for heliophysics and beyond concept paper for nrc space studies board october 2010 them insensitive to unwanted effects from changing scenes, was a main driver to develop an shs instrument for atmospheric remote sensing in the thermal infrared englert et al. The present subject matter is directed to a device for spectroscopy. A spatial heterodyne spectrometer shs is tested for the first time in combination with laserinduced breakdown spectroscopy libs. The probe and homodyne oke signals can be filtered out, leaving the heterodyne frequency signal for detection. Analysis and classification of liquid samples using. Spatial heterodyne spectroscopy by abc def on prezi. In this paper, a spatial heterodyne spectrometer based on the machzehnder interferometer mzshs is proposed. We demonstrate measurements of oh absorption spectra in the postflame zone of a mckenna burner using spatial heterodyne spectroscopy shs. Analysis and classification of liquid samples using spatial. Effect and implementation of flat field correction of a spatial heterodyne spectrometer. Oh absorption spectroscopy in a flame using spatial heterodyne spectroscopy. Spatial heterodyne spectroscopy shs is used for quantitative analysis. Spatial heterodyne spectroscopy shs is a fouriertransform spectroscopic.
A spatial heterodyne spectrometer has a two beam dispersive interferometer which includes a diffraction grating as a beam splittercombiner. Part of thechemistry commons this open access dissertation is brought to you by scholar commons. Spatial heterodyne spectrometer based on the machzehnder. Spatial heterodyne spectroscopy shs is used for quantitative analysis and classification of liquid samples. Fourier transform spectroscopy, fts 20, arlington, va, united states, 623. The fundamental principles underlying shs and its basic properties have been presented previously by harlander, reynolds, and roesler. The spectral range of traditional spatial heterodyne raman spectrometer shrs is limited by its spectral resolution and the number of detector elements.
Raman spectroscopy is a wellknown method for analysis and identification of chemical samples. Shs is basically a michelson interferometer with the return mirrors replaced by fixed. Doppler asymmetric spatial heterodyne dash spectroscopy. In this paper we present some recent developments in optical coherence imaging interferometric systems that open new diagnostic capabilities for next generation devices. Article information, pdf download for analysis and classification of. A modified spatial heterodyne spectrometer shs is used for measuring atomic emission spectra with high resolution. Standoff raman observations using a spatial heterodyne. The evolution of the design from a paraxial layout to a final working system is detailed, showing how the basic ideas outlined by the inventors of the ishs concept were realized in an instrument operating in the long wave ir. An alternative option is to use a spatial heterodyne spectrometer shs, first described by harlander et al 1992 11.
Evaluation of a spatial heterodyne spectrometer for raman. The light signal is compared with standard or reference light from a local oscillator lo that would have a fixed offset in frequency and phase from the signal if the latter carried null. Design and modeling of a tunable spatial heterodyne spectrometer. Spatial heterodyne imager for mesospheric radicals shimmer. Osa concerning the spatial heterodyne spectrometer.
In this paper a method for correcting the radial distortion of interferograms generated by a spatial heterodyne spectrometer system is presented. Us9200961b2 systems and methods for high resolution. Osa analysis and correction of distortions in a spatial. Merrimack college, 2011 a thesis submitted in partial ful llment of the requirements for the degree of master of science in the chester f. The probe and homodyne oke signals can be filtered. Raman spectroscopic detection using a twodimensional. Spatial heterodyne raman spectroscopy surrey research. Fly in space, for the first time, a monolithic spatial heterodyne spectrometer shs to increase the technical readiness level for this innovative optical technique observe mesospheric oh hydroxyl on a global scale at all daytime local times to investigate. The shs can be made monolithic by fusing all of the main optical elements into a single block with no moving parts. Us5059027a spatial heterodyne spectrometer and method. Optical heterodyne detection is a method of extracting information encoded as modulation of the phase, frequency or both of electromagnetic radiation in the wavelength band of visible or infrared light.
Pdf planar waveguide spatial heterodyne spectrometer. The spatial heterodyne spectrometer shs combines the high resolution and throughput of conventional interferometers with extreme robustness. Roesler, spatial heterodyne spectroscopy for the exploration of diffuse interstellar emission lines at farultraviolet wavelengths. Raman spectroscopic detection using a twodimensional spatial. Development of a spatial heterodyne raman spectrometer with. The light signal is compared with standard or reference light from a local oscillator lo that would have a fixed offset in frequency and. We describe the development of a nearultraviolet spatial heterodyne spectrometer designed for remote sensing of the global distribution. This method uses the fourier transform of the interferogram imaged on the detector by stationary diffraction gratings.
Flatfielding in spatial heterodyne spectroscopy osa. Here we describe the spatial heterodyne imager for chemicals and atmospheric detection shimcad, a spatial heterodyne spectroscopy shs instrument for the lwir. Shera is a novel design for a compact planetary exploration raman spectrometer using spatial heterodyne spectroscopy. The development of a spatial heterodyne spectrometer for.
Shrs has no moving parts and can be built with rugged, compact packages, making it extremely suitable for planetary exploration. The optical design for an ir imaging spatial heterodyne spectrometer is described. Spatial heterodyne spectroscopy shs is a novel spectral analysis technique that is being applied for raman spectroscopy of minerals. Spatial heterodyne imager for mesospheric radicals. The shs does not require scanning to function at its full resolving power. The device also includes a second heterodyne spectrometer configured to receive raman wavelengths from the sample.
Concerning the spatial heterodyne spectrometer osti. The pattern is recorded on an imaging detector and fourier transformed to recover the input stream. Spatial heterodyne spectrometer for transmissionraman. Spatial heterodyne spectroscopy shs is a relatively novel interferometric technique similar to the. Spatial heterodyne spectropolarimetry systems for imaging.
The spatial heterodyne observations of water instrument show is a limbsounding satellite prototype that utilizes the spatial heterodyne spectroscopy shs technique, operating in a limbviewing. Pdf oh absorption spectroscopy in a flame using spatial. Shs is a version of a michelson interferometer with no moving parts and with diffraction gratings in place of mirrors. Spatial heterodyne raman spectroscopy shrs is a type of method for the detection of raman spectra and can achieve a very high spectral resolution.
Compared to conventional fouriertransform spectroscopy that measures interferogram samples sequentially in the time domain, shs is insensitive to a changing scene. Objectives the objective of the dash development effort is to increase the trl of the innovative dash spatial heterodyne spectroscopy shs technique for future spacebased thermospheric wind observations. Raman scattering is a weak process, thus collecting as much light as possible is vital if good quality. Spatial heterodyne spectroscopy shs is a fouriertransform spectroscopic technique that simultaneously records all path differences using a detector array.
However, in shs, the latter terminate at fixed, tilted gratings that impose a wavelengthdependent tilt onto the diffracted wavefronts. Overview the instrument scientific background my project scientific background stephan 2001 harlander 2002 local interstellar medium doppler velocity measurements 3 kms r 100,000 1 pm sounding rocket earths middle atmosphere oh spectral lines r 52,000 6 pm satellite. Carlson center for imaging science of the college of science rochester institute of technology july 29, 20. Spatial heterodyne imager for mesospheric radicals on. In optical kerr effect oke spectroscopy, optical heterodyning of the oke signal and a small part of the probe signal produces a mixed signal consisting of probe, heterodyne okeprobe and homodyne oke signal. This paper presents the theoretical basis of shs and its application for raman measurements of calcite, quartz and forsterite in marble, copper ore and nickel ore, respectively. Osa flatfielding in spatial heterodyne spectroscopy. However, in the basic theory of shs, the relationship between the wavenumber and the frequency of the interferogram is approximated to be linear.
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