A flexible eye-safe lidar instrument for elastic-backscatter and DIAL

Iain Robinson, Jim Jack, Cameron Rae, John Moncrieff

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Developments in lidar have been driven largely by improvements in two key technologies: lasers and detectors. We describe here a lidar instrument for atmospheric remote sensing using the elastic-backscatter and differential-absorption lidar (DIAL) techniques. The instrument features an all-solid-state laser source combined with a flexible approach to detection providing portability, eye-safe operation and high sensitivity. The system is built around a custom-designed Newtonian telescope with a 0.38 m diameter primary mirror. Laser sources and detectors attach directly to the side of the telescope allowing for flexible customization with a range of equipment. The laser source is based on an optical parametric oscillator (OPO). The OPO is pumped by a neodymiumbased diode-laser pumped solid-state laser and angle-tuned by rotating the nonlinear conversion crystal. This provides a wide range of available wavelengths suitable for lidar within the 1.55 µm to 3.10 µm spectral region, where there exists a relatively high exposure limit for eye safety. The OPO delivers 1 mJ output pulse energy which is expanded and then transmitted coaxially from the telescope. Our goal is to make vertically-resolved measurements of greenhouse gas concentrations using DIAL. The source can rapidly be tuned between the on-line and off-line wavelengths to make a DIAL measurement. The use of the 1.6 µm wavelength region allows for several detection schemes. Whilst photodiode detectors are a very low-cost solution their limited sensitivity restricts the maximum range over which a signal can be detected. We therefore have designed the instrument to support alternative detection schemes including avalanche photodiodes (APDs).
Original languageEnglish
Title of host publicationProceedings of SPIE
Publication statusPublished - 1 Nov 2012
EventSPIE Remote Sensing 2012 - Edinburgh, United Kingdom
Duration: 24 Sep 201227 Sep 2012


ConferenceSPIE Remote Sensing 2012
Country/TerritoryUnited Kingdom


  • Absorption
  • Atmospheric sensing
  • Avalanche photodetectors
  • Avalanche photodiodes
  • Backscatter
  • Crystals
  • Equipment and services
  • Eye
  • Laser eye protection


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