Editing Infrared (section)

=== Commonly used subdivision scheme ===

A commonly used subdivision scheme is:<ref name="Byrnes">{{Cite book |last=Byrnes |first=James |title=Unexploded Ordnance Detection and Mitigation |publisher=Springer |year=2009 |isbn=978-1-4020-9252-7 |pages=21–22 |bibcode=2009uodm.book.....B}}</ref><ref name="RP-photonics">{{Cite web |title=Infrared Light |url=https://www.rp-photonics.com/infrared_light.html |url-status=live |archive-url=https://web.archive.org/web/20210801132547/https://www.rp-photonics.com/infrared_light.html |archive-date=1 August 2021 |access-date=20 July 2021 |website=RP Photonics Encyclopedia |publisher=RP Photonics}}</ref><ref>{{Cite web |date=2024-09-16 |title=Definition of NEAR-INFRARED |url=https://www.merriam-webster.com/dictionary/near-infrared |access-date=2024-10-02 |website=www.merriam-webster.com |language=en}}</ref>

{| class="wikitable"
|-
! Division&nbsp;name
! Abbreviation
! Wavelength
! Frequency
! Photon&nbsp;energy
! Temperature{{efn-lr|name=†|Temperatures of black bodies for which spectral peaks fall at the given wavelengths, according to the wavelength form of [[Wien's displacement law]].<ref>{{Cite web |title=Peaks of Blackbody Radiation Intensity |url=http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/wien3.html |url-status=live |archive-url=https://web.archive.org/web/20110318195600/http://hyperphysics.phy-astr.gsu.edu/Hbase/quantum/wien3.html |archive-date=18 March 2011 |access-date=27 July 2016}}</ref>}}
! Characteristics
|-
! Near-infrared
| NIR, IR-A ''DIN''
| 0.75–1.4&nbsp;[[μm]]
| 214–400&nbsp;[[Terahertz (unit)|THz]]
| 886–1,653&nbsp;[[meV]]
| {{convert|3864|–|2070|K|C|lk=on|disp=br()}}
| Goes up to the wavelength of the first [[water absorption]] band, and commonly used in [[fiber optic]] telecommunication because of low attenuation losses in the SiO<sub>2</sub> glass ([[silica]]) medium. [[Image intensifier]]s are sensitive to this area of the spectrum; examples include [[night vision]] devices such as night vision goggles. [[Near-infrared spectroscopy]] is another common application.
|-
! Short-wavelength infrared
| SWIR, IR-B ''DIN''
| 1.4–3&nbsp;μm
| 100–214&nbsp;THz
| 413–886&nbsp;meV
| {{convert|2070|–|966|K|C|lk=on|disp=br()}}
| Water absorption increases significantly at 1,450&nbsp;nm. The 1,530 to 1,560&nbsp;nm range is the dominant spectral region for long-distance telecommunications (see [[Fiber-optic communication#Transmission windows|transmission windows]]).
|-
! {{anchor|MidIR|MWIR|IIR|IR-C}} Mid-wavelength infrared
| MWIR, IR-C ''DIN''; MidIR.<ref name="rdmag20120908">{{Cite news |date=August 14, 2012 |title=Photoacoustic technique 'hears' the sound of dangerous chemical agents |url=http://www.rdmag.com/News/2012/08/Chemistry-Test-Measurement-Photonics-Photoacoustic-technique-hears-the-sound-of-dangerous-chemical-agents/?et_cid=2797047&et_rid=54719290&linkid=http%3a%2f%2fwww.rdmag.com%2fNews%2f2012%2f08%2fChemistry-Test-Measurement-Photonics-Photoacoustic-technique-hears-the-sound-of-dangerous-chemical-agents |url-status=live |archive-url=https://web.archive.org/web/20240922080442/https://www.rdworldonline.com/ |archive-date=September 22, 2024 |access-date=September 8, 2012 |work=[[R&D Magazine]] | at=rdmag.com}}</ref> Also called intermediate infrared (IIR)
| 3–8&nbsp;μm
| 37–100&nbsp;THz
| 155–413&nbsp;meV
| {{convert|966|–|362|K|C|lk=on|disp=br()}}
| In guided missile technology the 3–5&nbsp;μm portion of this band is the atmospheric window in which the seekers of passive IR 'heat seeking' missiles are designed to work, homing on to the [[infrared signature]] of the target aircraft, typically the jet engine exhaust plume. This region is also known as thermal infrared.
|-
! Long-wavelength infrared
| LWIR, IR-C ''DIN''
| 8–15&nbsp;μm
| 20–37&nbsp;THz
| 83–155&nbsp;meV
| {{convert|362|–|193|K|C|lk=on|disp=br()}}
| The "thermal imaging" region, in which sensors can obtain a completely passive image of objects only slightly higher in temperature than room temperature – for example, the human body – based on thermal emissions only and requiring no illumination such as the sun or moon or an infrared illuminator. This region is also called the "thermal infrared".
|-
! [[Far-infrared]]
| FIR
| 15–1,000&nbsp;μm
| 0.3–20&nbsp;THz
| 1.2–83&nbsp;meV
| {{convert|193|–|3|K|C|lk=on|disp=br()}}
| (see also [[far-infrared laser]] and [[far-infrared]])
|}
{{thermal image comparison}}
NIR and SWIR together is sometimes called "reflected infrared", whereas MWIR and LWIR is sometimes referred to as "thermal infrared".