Pulsed wideband IR thermal source

Author

Lainé, D.C. ; Al-Jourani, M.M. ; Carpenter, S. ; Sedgbeer, M.

Author_Institution

Dept. of Phys., Keele Univ., UK

Volume

144

Issue

5

fYear

1997

fDate

10/1/1997 12:00:00 AM

Firstpage

315

Lastpage

322

Abstract

A pulsed mid-IR thermal source based on electrical heating of a thin metal alloy foil up to red heat (~900°C) and cooled by its own radiation has been studied. The device, with emitting area diameters ranging from 25 mm to 1.7 mm, is based on a suspended bispiral metal foil geometry which offers substantial thermal isolation from the supporting structure. The infrared emission is two sided, but the reverse side radiation may be reflected through the plane of the bispiral heater to enhance the total forward emission. Practical devices are described in respect of their mechanical, electrical and infrared emitting properties. An encapsulated form of the smallest device incorporates an infrared transmitting window and infrared beam directivity and intensity-enhancing focusing reflector, and has a typical modulation depth of 85% at 10 Hz. Thermal target and gas detector applications of these sources are discussed

Keywords

electric heating; emissivity; foils; high-temperature techniques; infrared sources; metallic thin films; 25 to 1.7 mm; 900 C; bispiral heater; electrical heating; emitting area diameters; encapsulated form; gas detector applications; infrared beam directivity; infrared emitting properties; infrared transmitting window; intensity-enhancing focusing reflector; modulation depth; pulsed mid-IR thermal source; red heat; reverse side radiation; supporting structure; suspended bispiral metal foil geometry; thermal isolation; thermal target detector applications; thin metal alloy foil; total forward emission;

fLanguage

English

Journal_Title

Optoelectronics, IEE Proceedings -

Publisher

iet

ISSN

1350-2433

Type

jour

DOI

10.1049/ip-opt:19971361

Filename

674334