Variable numerical-aperture temporal-coherence measurement of resonant-cavity LEDs

Author

Coutinho, Ricardo C. ; Selviah, David R. ; Oulton, Rupert F. ; Gray, Jonathan W. ; Stavrinou, Paul N. ; Griffiths, Hugh D. ; Parry, Gareth

Author_Institution

Dept. of Electron. & Electr. Eng., Univ. Coll. London, UK

Volume

21

Issue

1

fYear

2003

fDate

1/1/2003 12:00:00 AM

Firstpage

149

Lastpage

154

Abstract

The first interferometric measurements of temporal-coherence length variation with numerical aperture (NA) are described for 650 nm, resonant-cavity light-emitting diodes (LEDs) agreeing with spectrally derived results. The interferometrically measured coherence length (22 μm to 32 μm) reduced by 37% for a 0.42 increase in NA. For a larger range of NA (0-1), this would give coherence lengths (10 μm-40 μm) lying in the gap between that of conventional LEDs (∼5 μm) and superluminescent diodes (∼60 μm).

Keywords

light coherence; light emitting diodes; light interferometry; optical resonators; optical testing; 10 micron to 40 micron; 22 to 32 micron; 650 nm; coherence length variation; conventional LEDs; interferometric measurements; interferometrically measured coherence length; numerical aperture; resonant-cavity LEDs; resonant-cavity light-emitting diodes; spectrally derived results; superluminescent diodes; variable numerical-aperture temporal-coherence measurement; Adaptive optics; Coherence; Interferometers; Length measurement; Light emitting diodes; Optical interferometry; Optical modulation; Optical noise; Resonance; Vertical cavity surface emitting lasers;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2003.809130

Filename

1190159