Laser hygrometer using a vertical-cavity surface-emitting laser (VCSEL) with an emission wavelength of 1.84 μm

Author

Lauer, Christian ; Szalay, Stefan ; Böhm, Gerhard ; Lin, Chun ; Köhler, Fabian ; Amann, Markus-Christian

Author_Institution

Walter Schottky Inst., Tech. Univ. Munchen, Garching, Germany

Volume

54

Issue

3

fYear

2005

fDate

6/1/2005 12:00:00 AM

Firstpage

1214

Lastpage

1218

Abstract

This paper presents a hygrometer setup for measuring the concentration of water vapor in air by means of infrared absorption spectroscopy. Recently developed vertical-cavity surface-emitting lasers (VCSELs) emitting near 1.84 μm are used as source of the infrared light. The laser hygrometer is able to calculate the density of water molecules from the measurement of one single light-current characteristic, without any additional reference measurement. The absolute and relative humidity are calculated from the water molecule density and the temperature of the ambient air.

Keywords

density measurement; humidity measurement; hygrometers; infrared spectroscopy; surface emitting lasers; absolute humidity; ambient air temperature; emission wavelength; infrared absorption spectroscopy; laser hygrometer; relative humidity; vertical-cavity surface-emitting laser; water molecule density; water vapor concentration measurement; Density measurement; Electromagnetic wave absorption; Humidity; Infrared spectra; Spectroscopy; Surface emitting lasers; Surface waves; Vertical cavity surface emitting lasers; Water; Wavelength measurement; Absorption spectroscopy; laser hygrometer; long-wavelength vertical-cavity surface-emitting lasers (VCSELs); trace gas sensing;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/TIM.2005.847195

Filename

1433197