<title>Light-emitting diodes for the 1.7-2.4 um wavelengths</title>

Abstract

The basic parameters of GaInAsSb mid-IR light emitting diodes designed for spectroscopic applications were shown. Two types of room temperature devices were presented: diodes for fixed emission wavelengths between 1.7 and 2.4 micrometers wavelengths and diodes tuned by drive current over wide wavelength range of 2.1-2.6 micrometers . The diodes were investigated for both continuous wave (CW) and pulse operation. The current-voltage characteristics, emission spectra, beam divergence, temperature shift of the emission band were presented and discussed. To find higher performance the output power was investigated versus pulse widths and repetition rates. It was reported that the GaInAsSb LED power was improved up to 2-3 times to the values as high as 3.7 mW CW and 82 mW pulse at (lambda) equals 1.94 micrometers as an example. It is shown that room-temperature operation, low electric power consumption, reduced cost and easy routine execution are the advantages to LEDs in comparison with spectrometers based on a diode lasers and thermal emitters. Sensitive and selective apparatuses for pollution detection, medicine and process control in the 1.7-2.4 micrometers wavelength range can be built on base of these LEDs as a source of radiation.