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In this paper we present a method for exactly cancelling the laser noise in a one-bounce unequal-arm Michelson interferometer. The method requries separate measurements of the phase difference in each arm, made by interfering the returning laser light in each arm with the outgoing light.
The Space Interferometry Mission (SIM) will be the first in-space, long-baseline Michelson Stellar Interferometer. SIM will perform precision astrometry at the micro-arcsecond accuracy level, which will be used to characterize planetary systems around stars within about ten parsecs of Earth and address a number of other key astrophysics projects. This paper provides a broad overview of the SIM Mission. Topics covered include: the science objectives, key top level requirements, how the mission will be implemented (technical and programmatic), technology development status, who the key players are in the SIM development, an assessment of where the project is today, and prognosis for the future.
The StarLight mission aimed to place the first formation flying optical interferometer into space in year 2006. Utilizing two spacecraft to form a long baseline Michelson interferometer, it would measure white light fringes on a number of partially resolved stars of magnitudes >5 in the wavelength range 600 to 1000nm. The interferometer baseline is variable between 30 and 125 m, and also has a fixed 1 m mode. The spacecraft are flown in a parabolic geometry which requires an optical delay line to build up more than 14m of delay on one arm of the interferometer. To obtain high fringe visibility, starlight wavefront, pointing and intensity must be preserved through 22 reflections from mirrors and beamsplitters. The alignment of a total of 27 optics is maintained through careful thermal design and the use of two actuated mirrors on each arm. This paper describes the optical layout in depth, including the beam combiner design which allows star tracking, optical system alignment and fringe formation on a single CCD. The effects of diffraction of the starlight transferred from a distant spacecraft and from optical surface imperfections are modeled. Other contributors to the visibility budget and the resulting variation of fringe visibility across the focal plane are discussed .
The Space Interferometry Mission (SIM) is a space-based 10 m baseline Michelson interferometer.
Deep Space 3 will fly a stellar optical interferometer on three separate spacecraft in heliocentric orbit: one spacecraft for the Michelson beam combining optics, and two spacecraft for each of the starlight apertures.
Michelson-type interferometer with a cat-eye reflector operates effectively even in the presence of random mechanical stresses. A cubical beamsplitter with dichroic surfaces permits operation in infrared or visible light.
Submillimeter wavelength radiometer receiver consisting of thermal radiation detector and Michelson interferometric modulator
Absolute pressure calibration system using a Michelson interferometer calibrates phase characteristics and pressure sensitivities of the transducers that monitor acoustic or aerodynamic pressure fields. The interferometer uses a helium-neon laser light source and interchangeable acoustic signal generators to produce acoustic waves.
System converts phase changes at optical frequencies to equal phase changes at RF. This system operates in conjunction with either a Michelson interferometer or conventional interferometers.
Emission spectrum of Venus between 8 and 13 microns observed with telescope using Michelson interferometer
Horizontal convecting air layer temperature gradient reversal measured with Michelson interferometer
Stellar spectra taken with rapid scanning Michelson interferometer, noting IR excess due to radiation from clouds surrounding stars
IR spectrum of NML Cygnus star with Michelson interferometer, noting CO bands and IR excess
IR spectrum of NML Cygnus star using rapid scanning Michelson interferometer, estimating temperature from CO bands
Double beam Michelson interferometer for middle IR with moving mirrors operating in constant velocity mode, applying method to atmospheric emission spectra
IR spectra of four carbon stars and Sirius obtained with Michelson interferometer, indicating diatomic carbon and CO bands
IR spectra of M stars and alpha Tau obtained with Michelson interferometer, observing molecular features and water vapor absorption
Jupiter and Saturn IR reflection spectra observed with Michelson interferometer- spectrometer, eliminating effects of terrestrial atmospheric absorption, solar spectral lines, etc