Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Mode–locked cavity–enhanced absorption spectroscopy

Titus Gherman and Daniele Romanini

Open Access Open Access

Abstract

We demonstrate the principle of cavity enhanced absorption with femtosecond modelocked lasers. The wide spectral coverage allowed by these sources makes this a promising high–sensitivity linear absorption technique. The uniformity of the modelocked frequency comb is the feature allowing effective injection of a high finesse cavity. The smooth and stable laser spectral profile guarantees a good background for the intracavity sample absorption spectrum, recorded by a spectrograph and a linear detector array. With a modelocked Ti:Sa laser and a cavity of finesse F ≃420 (F/π is the enhancement factor) we obtain a 4 nm section of a weak overtone band in 40 ms with 0.2cm-1resolution, and a detection limit of 2 × 10-7/cm/√Hz.

©2002 Optical Society of America

Full Article  |  PDF Article
More Like This
Cavity-enhanced absorption spectroscopy of molecular oxygen

Livio Gianfrani, Richard W. Fox, and Leo Hollberg
J. Opt. Soc. Am. B 16(12) 2247-2254 (1999)

High-speed off-axis Cavity Ring-Down Spectroscopy with a re-entrant configuration for spectral resolution enhancement

Jérémie Courtois, Ajmal Khan Mohamed, and Daniele Romanini
Opt. Express 18(5) 4845-4858 (2010)

Cavity-enhanced spectroscopy in optical fibers

Manish Gupta, Hong Jiao, and Anthony O’Keefe
Opt. Lett. 27(21) 1878-1880 (2002)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)
Fig. 1.
Fig. 1. Schematic diagram of the experimental setup: I is an optical isolator, PD are photodiodes, PH is a pinhole, L1 and L2 are lenses, M1 and M2 are cavity mirrors, and PZT is a piezoelectric actuator.

Download Full Size | PDF

Fig. 2.
Fig. 2. Cavity transmission as a function of displacement from “magic point”. These oscilloscope traces correspond to a piezoelectric scan of about 1 λ.

Download Full Size | PDF

Fig. 3.
Fig. 3. Spectra transmitted by the cavity for different displacements from magic point. Peaks correspond to groups of transmitted modes, unresolved by the spectrograph. Smaller peaks are due to excitation of transverse cavity modes.

Download Full Size | PDF

Fig. 4.
Fig. 4. Cavity transmission with length modulation around magic point. a) Cavity filled with acetylene, empty cavity, and laser spectrum. Intensities have been arbitrarily adjusted for clarity. b) Ratio of cavity transmission with/without acetylene over laser spectrum.

Download Full Size | PDF

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

L eff = F π ℓ ≃ 120 m .
T c ( ν ) ≃ T 2 1 − R 2 exp ( − 2 α ( ν ) ℓ ) .
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use