optical interferometer
(interferometer of visible light)
An optical interferometer is an interferometer for
visible light, and/or nearby portions of the neighboring
bands, infrared and ultraviolet.
Use of them is called optical interferometry.
Some research-telescope optical instruments
incorporate optical interferometry internally, e.g.,
a Michelson interferometer in an imaging Fourier transform spectrometer.
Gravitational-wave detectors such as LIGO also incorporate them.
A grating within a spectroscope works by interference,
but generally is not termed an interferometer.
Optical interferometers analogous to astronomical radio and microwave
interferometers have been created, for measurements and for images with
a very fine angular resolution, functioning by analyzing interference
of the light entering two or more optical telescopes.
Unlike radio interferometers, which create the interference
between electronic signals picked up by antennas, optical
interferometers create the interference optically before
sensing the light. The wave frequency is too high
to handle with analogous electronics.
There are significant challenges in designing, building, and
operating optical interferometers, which require extremely
precise, adjustable optics.
Otherwise they would be in more common use. Examples:
- CHARA (Center for High Angular Resolution Astronomy).
- KI (Keck Interferometer).
- LBTI (Large Binocular Telescope Interferometer).
- VLTI (Very Large Telescope Interferometer).
- NPOI (Navy Precision Optical Interferometer).
- SUSI (Sydney University Stellar Interferometer).
- MRO Interferometer (Magdalena Ridge Observatory Interferometer).
Past examples:
- COAST (Cambridge Optical Aperture Synthesis Telescope).
- PTI (Palomar Testbed Interferometer).
- I2T (Interféromètre a 2 Télescopes).
- GI2T (Grand Interféromètre a 2 Télescopes).
- IOTA (Infrared Optical Telescope Array).
- SOIRDETE (Synthése d'Ouverture en Infra Rouge avec Deux Telescopes) infrared.
A particular type of optical interferometer, an
intensity interferometer, operates by different principles,
not using wave interference (as do those listed above).
In discussions of both types, the term amplitude interferometer is
sometimes used for those using wave interference.
(interferometry,visible light)
Further reading:
https://en.wikipedia.org/wiki/Astronomical_optical_interferometry
https://www.naoj.hawaii.edu/staff/guyon/15teaching.web/02AstrOptics2013.web/wdir.web/AstrOpt2013_12interf01.pdf
http://nexsci.caltech.edu/workshop/2003/2003_MSS/07_Monday/history_030706a.pdf
https://academic.oup.com/astrogeo/article/53/2/2.14/212481
http://www.aoc.nrao.edu/events/synthesis/2004/presentations/HaniffOpticalInterferometry.pdf
http://physics.gmu.edu/~hgeller/astr402/HinzInterfer1.pdf
Referenced by pages:
angular resolution
CHARA
COAST
Colossus Telescope
European Southern Observatory Very Large Telescope (ESO VLT)
GI2T
high-resolution imaging
intensity interferometer
interferometer
interferometry
IOTA
Keck Observatory
Large Binocular Telescope (LBT)
Lowell Observatory
Mount Wilson Observatory (MWO)
MRO Interferometer (MROI)
Narrabri Stellar Intensity Interferometer (NSII)
Navy Precision Optical Interferometer (NPOI)
Palomar Observatory
Palomar Testbed Interferometer (PTI)
SUSI
VERITAS
visibility
Index