A tunable Ce:LiCAF laser is pumped by a CLBO crystal pumped by a doubled Nd:YLF laser running at 1 kilohertz. The UV tunable Ce:LiCAF laser produces two UV pulses between 280 to 295 nanometers. These pulses are transmitted into the atmosphere to profile the concentration of ozone as a function of altitude

Carrion, William

De Young, Russell

Ganoe, Rene

Pliutau, Denis

NASA Technical Reports Server

Solid State Mobile Lidar for Ozone Atmospheric Profiling 
 
Russell De Young 
Science Directorate, MS401A, NASA Langley Research Center, Hampton, VA 23681 
Russell.j.deyoung@nasa.gov 
 
William Carrion 
Coherent Applications Inc., Hampton, VA 23681 
 
Denis Pliutau and Rene Ganoe 
Science Systems and Applications Inc. Hampton, VA 23681 
 
 
Abstract: A tunable Ce:LiCAF laser is pumped by a CLBO crystal pumped by a doubled Nd:YLF 
laser running at 1 kHz. The UV tunable Ce:LiCAF laser produces two UV pulses between  280 to 
295nm. These pulses are transmitted into the atmosphere to profile the concentration of ozone as a 
function of altitude. 
OCIS codes: (010.0010) Atmospheric and Ocean Optics; (010.0280) Remote sensing and sensors  
 
 
1. Introduction  
A compact differential absorption lidar (DIAL) system has been developed at NASA Langley Research Center to 
provide ozone, aerosol and cloud atmospheric measurements in a mobile trailer for ground-based atmospheric ozone 
campaigns.  Since ozone is a pollutant in the lower atmosphere, it is important to understand its generation and 
transport for air-quality pollution monitoring and mitigation. This lidar will be integrated into the Air Quality lidar 
Network (AQLNet) currently made up of four other ozone lidars across the country.  
2. Lidar Configuration 
The lidar system consists of a UV and green laser transmitter, a telescope and an optical signal receiver box with 
associated (Licel) photon counting and analog channels as show in Fig. 1. The laser transmitter consist of a Coherent 
Evolution 30 TEM00 1-kHz diode pumped Q-switched Nd:YLF inter-cavity doubled laser pumping a Ce:LiCAF 
tunable UV laser with all the associated power and lidar control support units on a single system rack[1].  A custom-
designed Ce:LiCAF tunable UV laser has a wavelength range of 280 to 295-nm that is selectable between two or 
more wavelengths as shown in Fig. 2.  The current wavelengths are online 286.4 nm and offline 293.1 nm.  The 527-
nm visible beam is transmitted into the atmosphere for aerosol measurements.  The CLBO fourth harmonic 262 nm 
pump beam is split by a beamsplitter into two pump beams that pump each face of the Ce:LiCAF crystal. A short 
laser cavity consisting of a 60% reflective (1m radius of curvature) output mirror, a dispersive prism and a flat HR 
mirror is used to produce the UV wavelengths. In order to produce different wavelengths, the high-reflectivity flat 
rear mirror is mounted on a servo controlled galvanometer motor to allow rapid tuning between the on and offline 
ozone wavelengths.  Typical laser results are 6.8-W at 527-nm, 800-mW at 262-nm and 130-mW at the UV 
transmitted wavelengths. The lidar receiver system consists of a receiver telescope with a 40-cm diameter 
parabolic mirror.  A fiber optic cable transmits the received signal from the telescope to the receiver box, which 
houses the detectors. A separate telescope with PMT and filter is used to sample the very near field to allow ozone 
profiles from 100-m above ground. 
 To obtain an ozone atmospheric measurement, the transmitter sends a laser pulse into the atmosphere at 
alternating on-line and off-line wavelengths (500Hz each line)[2].  The 527-nm green laser output is always 
transmitted giving a return from atmospheric aerosols. The system has been configured to enable mobile operation 
from a trailer which is environmentally controlled, and is towed with a truck to sites that are equipped with power.  
The objective is to make the system mobile such that it can be setup at remote sites to support major air quality field 
campaigns. 
3. Ozone Lidar Results 
Figure 3 is an example of an ozone curtain atmospheric plot in the Hampton, VA on September 24, 2013 starting at 
7:52 AM local time showing the concentration of atmospheric ozone in parts per billion volume as a function of 
altitude. The ozone concentration is color coded. In the example the ozone concentration is shown from 600-m to 
https://ntrs.nasa.gov/search.jsp?R=20160005088 2019-08-31T03:46:16+00:00Z
3000-m. The ozone above the boundary layer at about 1500-m is probably transported from Northern Virginia from 
back trajectory analysis. Below the boundary layer, ozone in generated locally from cars and industrial processes. 
During the day sunlight increases the atmospheric temperature resulting in increased ozone in the boundary layer. 
This lidar system demonstrates the ability to deploy small mobile ozone lidars for remote sensing measurements at 
any location. 
 
 
 
 
 
 
 
 
 
 
Fig. 1 Overall ozone lidar schematic.    Fig.2 Laser transmitter schematic. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fig. 3 Example of curtain plot of ozone showing ozone transport from Northern Virginia above the boundary layer 
and local ozone generation below the boundary layer. 
 
4. References 
 
[1] Fromzel, V.A., Prasad, C.R., Petrosyan, K.B., Liaw, Y., Yakshin, M.A., Shi, W. and De Young, R.J.: Tunable, Narrow Linewidth, High 
Repetition Frequency Ce:LiCAF Lasers Pumped by the Fourth Harmonic of a Diode-Pumped Nd:YLF Laser for Ozone DIAL Measurements. 
Advances in Optical and Photonics Devices, Ed. Ki Young Kim, ISBN 978-953-7619-76-3, Intech, January 2010. 
[2]. Denis Pliutau, Russell DeYoung, UV Lidar Receiver Analysis for Tropospheric Sensing of Ozone,  NASA/TM-2013-218038, 2013. 
 
 
 
 
 
 


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