Coherent combination of micropulse tapered amplifiers at 828 nm for direct-detection LIDAR applications (original) (raw)

A Compact, Flexible, and Robust Micropulsed Doppler Lidar

Journal of Atmospheric and Oceanic Technology, 2020

This work details a master oscillator power amplifier (MOPA) microjoule-class pulsed coherent Doppler lidar system configuration designed to measure line-of-sight wind velocities and backscatter intensity of atmospheric aerosols. The instrument is unique in its form factor. It consists of two physically separated modules connected by a 10 m umbilical cable. One module hosts the transceiver, which is composed of the telescope, transmit/receive (T/R) switch, and high-gain optical amplifier, and is housed in a small box (34.3 cm × 34.3 cm × 17.8 cm). The second module contains the data acquisition system and several electro-optical components. This form factor enables deployments on platforms that are otherwise inaccessible by commercial and research instruments of similar design. In this work, optical, electrical, and data acquisition components and configurations of the lidar are detailed and two example deployments are presented. The first deployment describes measurements of a cont...

Micropulse water vapor differential absorption lidar: transmitter design and performance

2012

An all diode-laser-based micropulse differential absorption lidar (DIAL) laser transmitter for tropospheric water vapor and aerosol profiling is presented. The micropulse DIAL (MPD) transmitter utilizes two continuous wave (cw) external cavity diode lasers (ECDL) to seed an actively pulsed, overdriven tapered semiconductor optical amplifier (TSOA). The MPD laser produces up to 7 watts of peak power over a 1 µs pulse duration (7 µJ) and a 10 kHz pulse repetition frequency. Spectral switching between the online and offline seed lasers is achieved on a 1Hz basis using a fiber optic switch to allow for more accurate sampling of the atmospheric volume between the online and offline laser shots. The high laser spectral purity of greater than 0.9996 coupled with the broad tunability of the laser transmitter will allow for accurate measurements of tropospheric water vapor in a wide range of geographic locations under varying atmospheric conditions. This paper describes the design and performance characteristics of a third generation MPD laser transmitter with enhanced laser performance over the previous generation DIAL system.

High-efficiency receiver architecture for resonance-fluorescence and Doppler lidars

Applied Optics, 2015

A high-efficiency lidar receiver architecture that emphasizes boosting the receiver collection efficiency of resonance-fluorescence and Doppler lidars has opened up new avenues of study for the mesosphere and lower thermosphere-extended (MLT-X) at sites in Boulder, Colorado, USA, and Cerro Pachón, Chile. Described in this work are in-depth considerations in the design, construction, and alignment of Na Doppler lidar receivers that have yielded signal levels typically 5-10 times higher per power-aperture product than any demonstrated in the literature, to these authors' knowledge, making studies of finescale MLT turbulence and tenuous thermospheric layers in Na possible with temperature and vertical wind capability for the first time. A lowering of the detection threshold by higher receiver collection efficiency at Cerro Pachón has enabled this Na Doppler lidar to extend its measurement range far higher into the thermosphere, to regions with Na density less than 3 cm −3. With renewed interest in the MLT-X region prompted by recent lidar discoveries of Fe in the thermosphere reaching 170 km at McMurdo, Antarctica, the receiver optimizations we have made now enable addressing an important need in the community. In addition, the higher spatial and temporal resolutions afforded by high signal-to-noise ratio, down to resolutions of ∼20 s and ∼20 m, promise to make the first direct measurements of eddy flux in the mesopause region possible. Results from deployment of optimized receivers at the Table Mountain Lidar Observatory in Boulder, the Andes Lidar Observatory at Cerro Pachón, and the Arecibo Observatory in Puerto Rico are presented to demonstrate the power and portability of our methods that are readily applicable to other lidar varieties, including, but not limited to, the newly developed Fe Doppler lidar and recently upgraded K Doppler lidar.

Multiwavelength micropulse lidar for atmospheric aerosol investigation

2010

Multiwavelength micropulse lidar (MML) designed for continuous atmospheric sounding is presented. In its optical emitter, a diode pumped pulsed Nd:YAG laser is used. The laser generates three wavelengths: 1064, 532 and 355 nm. Energies of light pulses are about 30, 15 and 7 μJ, respectively, while their repetition rate is 2 kHz. Returning light is collected by a Cassegrain telescope with the mirror of 170 mm in diameter. Then, the signal is spectrally separated by a polichromator built with dielectric interference and colour filters. Detection of the signals is performed with three photomultipliers and a multiscaling photon counter. Preliminary results of investigation of aerosol properties during COAST 2009 experiment on the Baltic Sea are presented.

Implementation Of Micropulse Lidar at 4.5 μm and 1.5 μm for Aerosol and Cloud Study

EPJ Web of Conferences, 2016

Identifying and quantifying ambient aerosols and their interactions with clouds are important for air-quality and climate studies. Advances in infrared technologies on fiber lasers, quantum cascade lasers and IR detectors have made developing micro-pulse (low energy) IR lidar systems operating in the infrared spectral range feasible. We present in this contribution a micropulse dual channel (IR wavelength) lidar system for studying aerosol and cloud optical properties. The system operates at 1.545 µm (6472.5 cm-1) and at 4.55 µm (2197.8 cm-1) with high repetition rates and microjoule pulses. The system is intended to be coupled with an existing UV, visible, near infrared lidar system at the city college of New York, part of the CREST lidar network Preliminary backscattered signals from this system are here presented and compared to SNR simulation.

Micropulse Lidar (MPL) Handbook

2006

The micropulse lidar (MPL) is a ground-based optical remote sensing system designed primarily to determine the altitude of clouds overhead. The physical principle is the same as for radar. Pulses of energy are transmitted into the atmosphere; the energy scattered back ...

Validar: a testbed for advanced 2-micron Doppler lidar

SPIE Proceedings, 2004

High-energy 2-µm lasers have been incorporated in a breadboard coherent Doppler lidar to test component technologies and explore applications for remote sensing of the atmosphere. Design of the lidar is presented including aspects in the laser transmitter, receiver, photodetector, and signal processing. Sample data is presented on wind profiling and CO 2 concentration measurements.

Integrated Micro-Photonics for Remote Earth Science Sensing (Impress) Lidar

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

We present recent progress on a wavelength tunable, pulsed laser source for laser spectroscopy of CO2 at 1572 nm. An integrated photonics design in indium phosphide (InP) is presented and compared to a fiber-componentbased implementation. Significant improvement in size, weight and complexity is demonstrated.

A two micron coherent differential absorption lidar development

Lidar Remote Sensing for Environmental Monitoring XI, 2010

A pulsed, 2-µm coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument measures atmospheric CO 2 profiles (by DIAL) from a ground platform. It allows the investigators to pursue subsequent in science-driven deployments, and provides a unique tool for Active Sensing of CO 2 Emissions over Night, Days, and Seasons (ASCENDS) validation that was strongly advocated in the recent ASCENDS Workshop.