Frequency chirped differential absorption LIDAR

A. Lytkine; W. Jäger; J. Tulip

doi:10.1117/12.689312

3 October 2006 Frequency chirped differential absorption LIDAR

A. Lytkine, W. Jäger, J. Tulip

Proceedings Volume 6367, Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing II; 63670J (2006) https://doi.org/10.1117/12.689312
Event: SPIE Remote Sensing, 2006, Stockholm, Sweden

Abstract

We present a novel concept design of a differential absorption LIDAR for open path trace gas sensing in the atmosphere. To perform a range-resolved gas sensing we propose to arrange a set of retroreflectors in the laser beam path to measure a differential absorption in adjacent sections. In validation experiments we used a pulsed DFB quantum cascade laser fabricated by Alpes Lasers. The laser was excited with 200-ns current pulses with a repetition rate of 10 kHz. The frequency chirp rate was found to increase from 7.7 to 1.0 cm^-1/μs as peak injection current was increased from 7.1, to 7.8 A. We utilized the frequency chirp at laser substrate temperature of 24.0 °C to scan the 967.0 - 968.5 cm^-1 spectral interval containing the absorption lines of CO₂ and NH3. We detected ~ 0.25 ppmv of NH₃ in nitrogen at atmospheric pressure using a double-pass gas cell with an effective absorption path of 2.4 m. Digital filtering of the spectra was shown to be effective in eliminating a high-frequency noise. To demonstrate range-resolved capabilities of the sensor we used two retroreflectors inserted into the laser beam. A differential absorption of CO₂ at 967.7 cm^-1 was measured with the gas cell placed in one of the sections. Our experiments indicate that the frequency chirped LIDAR can be used for open path spectroscopy of NH₃ over the ranges up to ~ 1 km with a spatial resolution of ~ 30 m and detection limit of ~ 20 ppbv per a 30-m section.

Citation Download Citation

A. Lytkine, W. Jäger, and J. Tulip "Frequency chirped differential absorption LIDAR", Proc. SPIE 6367, Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing II, 63670J (3 October 2006); https://doi.org/10.1117/12.689312

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available