Highlights

The author

Robert W. Bogue is based at Robert Bogue and Partners, Technology and Business Consultants, Crockham Hill, Kent, UK. He is an Associate Editor for Sensor Review.

Keywords

Gas, Detection, Lasers

Abstract

Describes a unique optical source, the quantum cascade laser (QCL) and its application to gas detection. The instruments can detect both nitric oxide and carbon monoxide at concentrations down to 10 ppbm at atmospheric temperature and pressure with a 1 m absorption path-length. A QCL operating at 5.8 ?m can be used during airborne surveys of atmospheric formaldehyde, a key intermediate in the oxidation of methane and other hydrocarbons which contribute to the formation of ozone precursors.

Electronic access

The research register for this journal is available at http://www.emeraldinsight.com/researchregister

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Introduction

Back in 1994, the US Bell Labs (Lucent Technologies) invented a unique optical source, the quantum cascade laser (QCL) and now, under a licensing agreement with Bell, Physical Sciences Inc. (PSI) has launched the world s first gas detectors based on this technology.

The PSI products employ the widely commercialised gas detection principle of infrared absorption spectroscopy but their unique feature is the use of a QCL as the optical source. A QCL is a minute sliver of semiconductor materials which constrains electrons within layers of...