Ultrasensitive detections in atomic and molecular physics: demonstration in molecular overtone spectroscopy

Ye, Jun; Ma, Lei; Hall, John L.

doi:10.1364/josab.15.000006

Cited by 383 publications

(234 citation statements)

References 46 publications

Supporting

Mentioning

230

Contrasting

Order By: Relevance

“…We employ cavity-enhanced FM spectroscopy (NICE-OHMS) [20,21], see Fig. 1, where the probe carrier is modulated at the FSR to create sidebands, in our case separated from the carrier by multiples of 500 MHz.…”

Section: Methodsmentioning

confidence: 99%

Nonlinear spectroscopy of Sr atoms in an optical cavity for laser stabilization

et al. 2015

Self Cite

View full text Add to dashboard Cite

We study the non-linear interaction of a cold sample of strontium-88 atoms coupled to a single mode of a low finesse optical cavity in the so-called bad cavity limit and investigate the implications for applications to laser stabilization. The atoms are probed on the weak inter-combination line |5s 2 1 S0 − |5s5p 3 P1 at 689 nm in a strongly saturated regime. Our measured observables include the atomic induced phase shift and absorption of the light field transmitted through the cavity represented by the complex cavity transmission coefficient. We demonstrate high signal-to-noise-ratio measurements of both quadratures -the cavity transmitted phase and absorption -by employing FM spectroscopy (NICE-OHMS). We also show that when FM spectroscopy is employed in connection with a cavity locked to the probe light, observables are substantially modified compared to the free space situation where no cavity is present. Furthermore, the non-linear dynamics of the phase dispersion slope is experimentally investigated and the optimal conditions for laser stabilization are established. Our experimental results are compared to state-of-the-art cavity QED theoretical calculations.

show abstract

Section: Methodsmentioning

confidence: 99%

Nonlinear spectroscopy of Sr atoms in an optical cavity for laser stabilization

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Because of their sensitivity, continuous-wave (c.w.) cavity-enhanced spectroscopies have significant potential for addressing these challenging applications 6,14,15 . However, the low mechanical or thermal tuning rates of c.w.…”

mentioning

confidence: 99%

Frequency-agile, rapid scanning spectroscopy

et al. 2013

View full text Add to dashboard Cite

Challenging applications in trace gas measurements require low uncertainty and high acquisition rates [1][2][3][4] . Many cavityenhanced spectroscopies exhibit significant sensitivity and potential 5,6 , but their scanning rates are limited by reliance on either mechanical or thermal frequency tuning 7 . Here, we present frequency-agile, rapid scanning spectroscopy (FARS) in which a high-bandwidth electro-optic modulator steps a selected laser sideband to successive optical cavity modes. This approach involves no mechanical motion and allows for a scanning rate of 8 kHz per cavity mode, a rate that is limited only by the cavity response time itself. Unlike rapidly frequency-swept techniques 8-11 , FARS does not reduce the measurement duty cycle, degrade the spectrum's frequency axis or require an unusual cavity configuration. FARS allows for a sensitivity of ∼2 3 10 212 cm 21 Hz 21/2 and a tuning range exceeding 70 GHz. This technique shows promise for fast and sensitive trace gas measurements and studies of chemical kinetics.A multitude of applications have emerged that require rapid sensing of trace gas species, encompassing areas as varied as greenhouse gas monitoring 1,4,12 , breath analysis 2,13 , explosive detection 3 and chemical process monitoring. Because of their sensitivity, continuous-wave (c.w.) cavity-enhanced spectroscopies have significant potential for addressing these challenging applications 6,14,15 . However, the low mechanical or thermal tuning rates of c.w. lasers have generally limited the use of these techniques to static or slowly varying analytes. Attempts to alleviate this limitation have relied on sweeping the laser frequency [8][9][10][11] , which can compromise the fidelity of the spectrum and the instrument sensitivity 16 and reduce the measurement duty cycle. We present a new approach for cavity ring-down spectroscopy 17 in which the laser frequency is rapidly stepped to successive resonances through the use of highbandwidth electro-optics. This technique, which we refer to as frequency-agile, rapid scanning (FARS) cavity ring-down spectroscopy, allows for ultrasensitive measurements in which the acquisition rate is limited only by the cavity response. Unlike earlier techniques [8][9][10][11]18,19 , FARS allows for spectra to be recorded without any dead time due to scanning of the laser frequency, offers a metrology-level frequency axis and utilizes a conventional Fabry-Pérot resonator rather than more unusual and cumbersome cavity configurations.This frequency stepping of the probe laser is enabled by the use of a microwave driver and a high-bandwidth electro-optic modulator (EOM) to generate a series of sidebands on the probe laser (Fig. 1). We then use the cavity as a spectral filter such that only a single, selected sideband is resonant. Thus, we are able to transfer the superior switching bandwidth and precision of microwave sources into the optical domain. Ring-downs are then initiated by simply switching off the microwave frequency, thus removing the need for an acousto-...

show abstract

“…In so doing, the laser intensity fluctuation, which occurs primarily at low frequency (kHz to DC), can be circumvented, as has been previously applied in other spectroscopic 11 and recently stimulated Raman scattering (SRS) microscopy 12 and two photon absorption microscopy 13 . In the scheme shown in Fig.…”

mentioning

confidence: 99%

“…In contrast, it is difficult to implement such modulation scheme for high sensitivity one-beam absorption measurement 11 .…”

mentioning

confidence: 99%