Subdoppler and doppler spectroscopy of dcn isotopomers in. Importantly, the sub doppler features can be measured as long as the laser carrier frequency lies within the doppler profile, thus removing the need for slow scanning or a priori knowledge of the frequencies of the sub doppler features. Sub doppler spectroscopy uses counterpropagating beams to generate a lamb dip centered at the rest frequency, where the width is determined instead by the much smaller homogeneous broadening. In classical spectroscopy a severe barrier to spectral resolution and measurement precision is often encountered because of the doppler effect. These measurements include transitions involving higher rotational levels than previously frequency measured in this band. Dopplerfree saturation spectroscopy max planck institut. Mccall1,2,a 1department of chemistry, university of illinois, urbana, illinois 61801, usa 2departments of astronomy and physics, university of illinois, urbana, illinois. A novel solid state source, based on a diode laser, a ybq fiber amplifier and a periodicallypoled ktiopo crystal, was developed, 4 having a continuous tunability range of 1. Rovibrational spectroscopy of the fundamental oh stretching mode of the transhoco radical has been studied via sub doppler highresolution infrared laser absorption in a discharge slitjet expansion. Journal of molecular spectroscopy 120, 414420 1986 hyperfine coupling constants of nco in a22. The electronically locked continuous wave ceas can be used for highly sensitive sub doppler absorption spectroscopy. Spectroscopy and doppler shift mit haystack observatory.
The vapour pressure, controlled by heating a commercial reference cell, is. In all the labs dealing with laser cooling and trapping of atoms, the technique of dopplerfree saturated absorption spectroscopy is frequently used as a tool for. Pdf subdoppler rotationally resolved spectroscopy of. Pdf frequencycombreferenced singlyresonant opo for. Doppler and subdoppler millimeter and submillimeter. Doppler and sub doppler millimeter and sub millimeter wave spectroscopy of key astronomical molecules. Hence, a single laser beam irradiation is sufficient to observe subdoppler resonances because of the transient atomic response, which. Introduction usually the laser beam diameter d is much less than the length of a gas cell fig. Sub doppler broadband multiheterodyne spectroscopy is proposed and experimentally demonstrated.
Sub doppler twophoton spectroscopy of 33 rydberg levels in atomic xenon excited at 2052 nm. New techniques for subdoppler spectroscopy of molecular ions. Pdf we report on the spectroscopy in a resonant vapor film, in a regime in which the inhomogeneous transit time induces a velocity selection. Sub doppler spectroscopy of molecular ions in laboratory plasmas is challenging given that ions have large collisional cross sections, which. Pdf subdoppler spectroscopy in a thin film of resonant. Subdoppler spectroscopy of molecular iodine around 541 nm.
We have carried out sub doppler resolution spectroscopy of the. Subdoppler modulation spectroscopy of potassium for laser. The transhoco radical is formed by discharge dissociation of h 2 o to form oh, which then combines with co and cools in the ne expansion to a rotational temperature of. We present a pulsed single longitudinal mode optical parametric oscillator that was recently constructed for sub doppler spectroscopic studies of transient species in a supersonic slit jet expansion environment. Doppler spectroscopy also known as the radialvelocity method, or colloquially, the wobble method is an indirect method for finding extrasolar planets and brown dwarfs from radialvelocity measurements via observation of doppler shifts in the spectrum of the planets parent star 880 extrasolar planets about 21. Pdf optogalvanic subdoppler spectroscopy in titanium. Sub doppler linewidth spectra of the q01 2 transition in deuterium d2 have been obtained by using a stimulated raman technique analogous to sub doppler ir saturation spectroscopy. Sub doppler optical frequency comb spectroscopy has the potential to dramatically reduce acquisition times. Using two laser frequency combs of slightly different repetition frequencies, we have recorded doppler free twophoton dualcomb spectra of atomic rubidium resonances of a width of 6 mhz, while simultaneously interrogating a spectral span of 10 thz.
Sub doppler excitation spectra of the s 1 1b 2uv 61 sub doppler resolution was obtained by combining optogalvanic detection with saturation. Heterodyne detection then yields sub doppler frequency discriminants suitable for stabilizing lasers in experiments with. Ideal primary data in atomic and molecular physics would include the energy levels of single isolated atoms and molecules, and an approximation to these is obtained from spectra of gases at low pressures. Subdoppler twophoton spectroscopy of 33 rydberg levels. Frequencycombreferenced singlyresonant opo for sub doppler spectroscopy. Subdoppler spectroscopy of the transhoco radical in the. Doppler spectroscopy is an indirect method for finding extrasolar planets and brown dwarfs. A simple supersonic jet discharge source for subdoppler. The saturation dip is detected by using an inverse raman technique to probe the. This thesis details research in developing new methods for performing highresolution sub doppler spectroscopy of molecular ions in the laboratory.
Frequency measurements and selfbroadening of subdoppler. Pdf we study modulation spectroscopy of the potassium d2 transitions at 766. Volume 104, number 5 chemical physics letters 17 february 1984 influence of magnetic field on the cage effect during photolysis of pbenzoquinone in npropanol i. Sub doppler opticaloptical doubleresonance spectroscopy of bao. Subdoppler optical frequency comb spectroscopy has the potential to dramatically reduce acquisition times and allow for rapid and accurate. Subdoppler spectroscopy with a cmos transmitter ieee. Osa subkilohertz linewidth roomtemperature midinfrared. Onephoton dicknarrowing absorption spectroscopy from a thin atomic vapor film can be extended to the twophoton case, in which the sub doppler absorption structures are obtained in a cascade. The performance of this crystal for doubling 1083 nm laser radiation is demonstrated for the first time. Laser absorption spectrometry las refers to techniques that use lasers to assess the concentration or amount of a species in gas phase by absorption spectrometry as optical spectroscopic techniques in general, and laserbased techniques in particular, have a great potential for detection and monitoring of constituents in gas phase.
Sub doppler resolution of atomic transitions is obtained by spatially resolved laser induced fluorescence in a diverging atomic beam created by laser ablation. Sub doppler excitation spectra of the s 1 1b 2uv 61 sub doppler spectroscopy of ch 2 j. Sub doppler twophotonexcitation rydberg spectroscopy of atomic xenon. Hall, sub doppler optical frequency reference at 1. The accuracy to which these frequencies can be determined is, ideally, limited only by the width of the excited state, which is the inverse of the lifetime. Request pdf a simple supersonic jet discharge source for subdoppler spectroscopy a spectral light source utilising a supersonic jet and a hollow cathode. We report on the narrowing of a roomtemperature midir quantum cascade laser by frequency locking it to a co2 sub doppler transition obtained by polarization spectroscopy.
Subdoppler spectroscopy in a thin film of resonant vapor. Pdf subdoppler modulation spectroscopy of potassium for laser. We report about possibilities of application of the optothermal detector ot for sub doppler spectroscopy experiments. We study modulation spectroscopy of the potassium d 2 transitions at 766. Atoms moving towards an observer appear to emit or absorb light at shorter wavelengths than atoms at rest, and atoms moving away appear to emit at longer wavelengths. Multiplexed subdoppler spectroscopy with an optical. A compact and lowpower complementary metal oxide semiconductor cmosbased transmitter with an operational bandwidth of 90105 ghz has been deployed as the radiation source in a highresolution sub doppler lambdip absorption spectrometer. Subdoppler twophotonexcitation rydberg spectroscopy of. We performed saturatedabsorption spectroscopy of h2 18o at 1. Sub doppler and doppler spectroscopy of dcn isotopomers in the terahertz region. Multiplexed subdoppler spectroscopy with an optical frequency comb.
Subdoppler spectroscopy by submicron thin cs vapour. Resonances are spatially separated by relativistic effects experienced between the probing radiation and the moving particles thus proving that it is a highquality atomic beam. We report high resolution sub doppler spectroscopy of molecular iodine hyperfine transitions around 541 nm. The journal of chemical physics 141, 101101 2014 communication.
Two experimental configurations are described that employ alternatively either three or four laser beams at two frequencies. The problems of precise measurement of length and absolute measurement of light frequency are considered. Pulsed single longitudinal mode optical parametric. Sub doppler optical frequency comb spectroscopy has. Sub doppler spectroscopy with a cmos transmitter abstract. Doppler free spectroscopy using two counterpropagating dualfrequency laser beams in alkali vapor cells has been demonstrated recently, providing the detection of highcontrast signreversed naturallinewidth sub doppler resonances.