Hybrid fiber/bulk laser source designed for CO and wind measurements at 2.05 µm: publisher's note.

This publisher's note contains a correction to Opt. Lett.49, 969 (2024)10.

Greenhouse gas monitoring using an IPDA lidar based on a dual-comb spectrometer.

We present the development of a multi-spectral, integrated-path differential absorption (IPDA) lidar based on a dual-comb spectrometer for greenhouse gas monitoring. The system uses the lidar returns from topographic targets and does not require retroreflectors. The two frequency combs are generated by electro-optic modulation of a single continuous-wave laser diode.

Hybrid fiber/bulk laser source designed for CO and wind measurements at 2.05 µm.

We present a hybrid fiber/bulk laser source designed for CO and wind monitoring using differential absorption LIDAR (DIAL) and coherent detection at 2.05 µm. This source features a master oscillator power amplifier (MOPA) architecture made of four fiber stages and one single-pass, end-pumped, bulk amplifier.

Electro-optic frequency comb based IPDA lidar: assessment of speckle issues.

We present a theoretical, numerical and experimental assessment of the impact of speckle on a dual electro-optic frequency comb (EOFC) based system for integrated path differential absorption (IPDA) measurements. The principle of gas concentration measurements in a dual EOFC configuration in the absence of speckle is first briefly reviewed and experimentally illustrated using a CH gas cell. A numerical simulation of the system performance in the presence of speckle is then outlined.

2.05-µm all-fiber laser source designed for CO and wind coherent lidar measurement.

This work reports on an all-fiber pulsed laser source for simultaneous remote sensing of concentration and wind velocity in the 2.05 µm region. The source is based on a polarization-maintaining master oscillator power amplifier (MOPA) architecture.

Long-wave infrared multi-wavelength IPDA lidar for standoff detection of chemical warfare agents: theoretical study.

We discuss and evaluate the expected performance of a tunable multi-wavelength integrated-path differential absorption lidar operating in the long-wave infrared between 7.5 and 11 µm, for standoff measurement of chemical agents. Interference issues with natural gas compounds throughout the entire 7.

Long-wave infrared multi-wavelength optical source for standoff detection of chemical warfare agents.

We have designed and built a wavelength-tunable optical source for standoff detection of gaseous chemicals by differential absorption spectrometry in the long-wave infrared. It is based on a nanosecond 2 µm single-frequency optical parametric oscillator, whose idler wave is amplified in large aperture Rb:PPKTP crystals. The signal and idler waves are mixed in crystals to produce single-frequency tunable radiation in the 7.

Performance assessment of a coherent DIAL-Doppler fiber lidar at 1645 nm for remote sensing of methane and wind.

We report on the performances of a coherent DIAL/Doppler fiber lidar called VEGA, allowing for simultaneous measurements of methane and wind atmospheric profiles. It features a 10µJ, 200 ns, 20 kHz fiber pulsed laser emitter at 1645 nm, and it has been designed to monitor industrial methane leaks and fugitive emissions in the environment. The system performance has been assessed for range-resolved (RR) and integrated-path (IP) methane measurements in natural background conditions (i.

Raman lidar for hydrogen gas concentration monitoring and future radioactive waste management.

A multi-channel Raman lidar has been developed, allowing for the first time simultaneous and high-resolution profiling of hydrogen gas and water vapor. The lidar measures vibrational Raman scattering in the UV (355 nm) domain. It works in a high-bandwidth photon counting regime using fast SiPM detectors and takes into account the spectral overlap between hydrogen and water vapor Raman spectra.

Tentative detection of clear-air turbulence using a ground-based Rayleigh lidar.

Atmospheric gravity waves and turbulence generate small-scale fluctuations of wind, pressure, density, and temperature in the atmosphere. These fluctuations represent a real hazard for commercial aircraft and are known by the generic name of clear-air turbulence (CAT). Numerical weather prediction models do not resolve CAT and therefore provide only a probability of occurrence.

Performance assessment and signal processing for range-integrated concentration measurement of gas species using supercontinuum absorption spectroscopy.

In this paper, we propose signal-processing tools adapted to supercontinuum absorption spectroscopy, in order to predict the precision of gas species concentration estimation. These tools are based on Cramer-Rao bounds computations. A baseline-insensitive concentration estimation algorithm is proposed.

Minimum description length approach for unsupervised spectral unmixing of multiple interfering gas species.

We address an original statistical method for unsupervised identification and concentration estimation of spectrally interfering gas components of unknown nature and number. We show that such spectral unmixing can be efficiently achieved using information criteria derived from the Minimum Description Length (MDL) principle, outperforming standard information criteria such as AICc or BIC. In the context of spectroscopic applications, we also show that the most efficient MDL technique implemented shows good robustness to experimental artifacts.

Performance evaluation of a dual fringe-imaging Michelson interferometer for air parameter measurements with a 355 nm Rayleigh-Mie lidar.

A new concept of spectrum analyzer is proposed for short-range lidar measurements in airborne applications. It implements a combination of two fringe-imaging Michelson interferometers to analyze the Rayleigh-Mie spectrum backscattered by molecules and particles at 355 nm. The objective is to perform simultaneous measurements of four variables: the air speed, the air temperature and density, and the particle scattering ratio.