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In thermal (heating) emission source of infrared radiation a wire is heated up by a current flow and emits
in a very wide range according to Planck`s law. The required spectral range is obtained by using special optical filters.
Sensors employing this type of radiation source have some certain drawbacks:
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- High electrical power consumption and low efficiency. Filter cuts only small part of wide emitted spectral range.
- Low speed of response.
- Heating infrared source practically can not be modulated by current.
- Short lifetime. Frequent catastrophic degradation takes place.
- Restricted possibilities for miniaturization due to high heat dissipation and necessity for using filters.
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LEDs and Photodiodes that cover 1600-5000nm spectral range were developed and their production was started at IBSG.
New Mid-Infrared LEDs posses certain advantages comparing to heating infrared radiation sources:
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- compactness (size of the standard LED chip is 0.3x0.3 mm)
- low electrical power consumption (down to 1 mW in pulse mode)
- high speed response (tens per nanoseconds)
- long lifetime (up to 100 000 hours)
- low cost in mass production
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Creation of Mid-infrared optoelectronic devices became possible due to qualitative technological break-through
in growing of latticed-matched heterostructures based on narrow band-gap substrates GaSb and InAs
that was achieved last decade in IBSG Co., Ltd in collaboration with Ioffe Institute, Russian Academy of Sciences.
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