CAVITY RINGDOWN SPECTROSCOPY AND HIGH SENSITIVITY ABSORPTION MEASUREMENT

Zhao Hong

Published Jan 1, 2001• 0 citations

Abstract

Cavity ring\|down spectroscopy is a novel spectroscopic technique used for high\|sensitivity measurement of absorption. It has been widely used in atomic, molecular and cluster spectroscopy, with an absorption sensitivity of 10 -6 —10 -14 cm -1 . The development of the cavity ring\|down technology and its application in absorption measurement are reviewed.

Related papers

Cavity ringdown heterodyne spectroscopy: High sensitivity with microwatt light power

Jun Ye, J. L. Hall

We present an ac heterodyne technique in cavity ringdown spectroscopy that permits $1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ absorption sensitivity with microwatt-level light power. Two cavity modes, one probing the empty cavity and the other probing intracavity absorption, are excited simultaneously but with their intensities temporally out of phase, with one mode decaying and the other rising. Heterodyne detection between the two modes reveals the dynamic time constants associated with the empty cavity and the additional intracavity gas absorption. The method offers a quick comparison between the on- and off-resonance information, a prerequisite to reaching the fundamental shot-noise limit. This simple and yet important improvement of cavity ringdown spectroscopy should lead to the enhanced performance of a wide range of applications.

Physical Review AMay 17, 200052 citations

Optical feedback frequency stabilized cavity ring-down spectroscopy

Johannes Burkart, D. Romanini, S. Kassi

We introduce optical feedback frequency stabilized cavity ring-down spectroscopy (OFFS-CRDS), a near-shot-noise-limited technique that combines kilohertz resolution with an absorption detection sensitivity of 5×10(-13) cm(-1) Hz(-1/2). Its distributed feedback laser source is stabilized to a highly stable V-shaped reference cavity by optical feedback and fine-tuned by means of single-sideband modulation. The stability of this narrow laser is transferred to a ring-down (RD) cavity using a new fibered Pound-Drever-Hall (PDH) locking scheme without a dedicated electro-optic phase modulator, yielding several hundred RD events per second. We demonstrate continuous coverage of more than 7 nm with a baseline noise of 5×10(-12) cm(-1) and a dynamic range spanning six decades. With its resonant intracavity light intensity on the order of 1 kW/cm2, the spectrometer was used for observing a Lamb dip in a transition of carbon dioxide involving four vibrational quanta. Saturating such a weak transition at 160 μW input power, OFFS-CRDS paves the way to Doppler-free molecular overtone spectroscopy for precision measurements of hyperfine structures and pressure shifts.

Optics LettersAug 4, 201461 citations

Cavity Ring-down Spectroscopy with behavior of Hybrid Cavity Structures

Muhammad Junaid Khan, Rida Batool Sheraliyat

Cavity ring-down (CRD) spectroscopy represents a direct absorption technique of sample absorption measurement. Instead of measuring the amount of the absorbed light, this technique determines the rate at which light intensity decays inside an optical cavity. When using a pulsed or continuous-wave light source, CRD spectroscopy offers considerably higher sensitivity as compared with conventional spectroscopy of absorption, making even very weak absorptions easy to detect.

physics.opticsCross-listedarXiv:2512.12241Dec 16, 2025

Rapid scanning cavity ring-down spectroscopy at the quantum noise limit

David A. Long, Adam J. Fleisher, Szymon Wójtewicz +2 more

We present an ultrasensitive cavity-enhanced technique for probing weak molecular absorptions. Recently, we have implemented heterodyne detection, which allowed for quantum-noise-limited detection and noise-equivalent absorption coefficients as low as 6×10−14 cm−1•Hz−1/2.

Jan 1, 20140 citations

Ultrasensitive Surface Spectroscopy with a Miniature Optical Resonator

Andrew C. R. Pipino

The number density and orientation of molecules at the surface of a total-internal-reflection-ring minicavity are probed with extremely high sensitivity in a novel realization of the cavity ring-down optical absorption experiment. The modes of the ultralow-loss cavity, which are excited by photon tunneling, have long lifetimes that are sensitive to the presence of absorbing species in the evanescent field near a cavity facet. The total-internal-reflection-ring cavity extends cavity ring-down spectroscopy to surfaces and condensed matter, permitting a wide range of novel fundamental studies and applications. Routine single molecule detection may ultimately be feasible.

Physical Review LettersOct 11, 199989 citations

THEORETICAL INVESTIGATION OF THE HIGH-RESOLUTION DOFPLER-FREE TWO-PHOTON CAVITY RING-DOWN LASER ABSORPTION SPECTROSCOPY OF ALKALI RYDBERG STATES

Mark Wladyslawski, Kevin K. Lehmann

Due to the phase-coherent relationship of intra-cavity pulse reflections leading to the narrow frequency-selectivity of the cavity, Cavity Ring-Down Laser Absorption Spectroscopy (CRLAS) is a promising method lo study Doppler-free two-photon absorption at resolutions at least two orders of magnitude better than the pulse bandwidth of even Fourier Transform Limited nsec pulsed lasers. The nonlinear absorption will lead to a nouexponential cavity decay with can be used to discriminate it from both linear absorption and intrinsic cavity loss. In this study, several issues have been examined in order to access the feasibility of obtaining the high-resolution two-photon absorption spectra of the Rydberg states of alkali dimers by this technique. Using atomic transition dipoles as an approximation, the laser intensities needed to elicit reasonable excitation were estimated, and found to be well within presently available levels. The importance of the various linewidth- limiting mechanism was also examined. The relative magnitudes of pressure broadening, AC Stark broadening, cavity stability, and time-of-flight broadening lead us to expect a resolution of $\\sim$1 MHz or better.

Jan 1, 19970 citations