Common-path interferometer

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A common-path interferometer is a class of interferometers in which the reference beam and sample beams travel along the same path. Examples include the Sagnac interferometer, Zernike phase-contrast interferometer, and the point diffraction interferometer. A common-path interferometer is generally more robust to environmental vibrations than a "double-path interferometer" such as the Michelson interferometer or the Mach–Zehnder interferometer. [1] Although travelling along the same path, the reference and sample beams may travel along opposite directions, or they may travel along the same direction but with the same or different polarization.

Contents

Double-path interferometers are highly sensitive to phase shifts or length changes between the reference and sample arms. Because of this, double-path interferometers have found wide use in science and industry for the measurement of small displacements, [2] refractive-index changes, [3] surface irregularities and the like. There are applications, however, in which sensitivity to relative displacement or refractive-index differences between reference and sample paths is not desirable; alternatively, one may be interested in the measurement of some other property.

Selected examples

Figure 1. Selected examples of common-path interferometers Selected common path interferometers.png
Figure 1. Selected examples of common-path interferometers

Sagnac

Sagnac interferometers are totally unsuited for measuring lengths or length changes. In a Sagnac interferometer, both beams emerging from the beamsplitter simultaneously go around all four sides of a rectangle in opposite directions and recombine at the original beamsplitter. The result is that a Sagnac interferometer is, to first order, completely insensitive to any movement of its optical components. Indeed, in order to make the Sagnac interferometer useful for measuring phase changes, the beams of the interferometer must be separated slightly so that they no longer follow a perfectly common path. Even with a slight beam separation, Sagnac interferometers offer excellent contrast and fringe stability. [4] Two basic topologies of the Sagnac interferometer are possible, differing in whether there are an even or odd number of reflections in each path. In a Sagnac interferometer with an odd number of reflections, such as the one illustrated, the wavefronts of the oppositely traveling beams are laterally inverted with respect to each other over most of the light path, so the topology is not strictly common-path. [5]

The best known use of the Sagnac interferometer lies in its sensitivity to rotation. The first accounts of the effects of rotation on this form of interferometer were published in 1913 by Georges Sagnac, who mistakenly believed that his ability to detect a "whirling of the ether" disproved relativity theory. [6] The sensitivity of present-day Sagnac interferometers far exceeds that of Sagnac's original arrangement. The sensitivity to rotation is proportional to the area circumscribed by the counter-rotating beams, and fibre optic gyroscopes, present-day descendants of the Sagnac interferometer, use thousands of loops of optical fibre rather than mirrors, such that even small to medium-sized units easily detect the rotation of the Earth. [7] Ring laser gyroscopes (not illustrated) are another form of Sagnac rotation sensor that have important applications in inertial guidance systems. [6]

Because of their exceptional contrast and fringe stability, interferometers using the Sagnac configuration played an important role in experiments leading to Einstein's discovery of special relativity, and in the subsequent defense of relativity against theoretical and experimental challenges. For example, one year before their famous experiment of 1887, Michelson and Morley (1886) performed a repeat of the Fizeau experiment of 1851, replacing Fizeau's setup with an even-reflection Sagnac interferometer of such high stability, that even placing a lighted match in the light path did not cause artifactual fringe displacement. [8] In 1935, Gustaf Wilhelm Hammar disproved a theoretical challenge to special relativity that attempted to explain away the null results of Michelson–Morley–type experiments as being mere artifact of aether-dragging, using an odd-reflection Sagnac interferometer. He could operate this interferometer in the open, on a high hilltop with no temperature control, yet still achieve readings of 1/10 fringe accuracy. [9] [10]

Point diffraction

Figure 2. Young's experiment - single- versus double-slit patterns Single slit and double slit3.jpg
Figure 2. Young's experiment – single- versus double-slit patterns

Another common-path interferometer useful in lens testing and fluid flow diagnostics is the point diffraction interferometer (PDI), invented by Linnik in 1933. [11] [12] The reference beam is generated by diffraction from a small pinhole, about half the diameter of the Airy disk, in a semitransparent plate. Fig. 1 illustrates an aberrated wavefront focused onto the pinhole. The diffracted reference beam and the transmitted test wave interfere to form fringes. The common-path design of the PDI brings to it a number of important advantages. (1) Only a single laser path is required rather than the two paths required by the Mach-Zehnder or Michelson designs. This advantage can be very important in large interferometric setups such as in wind tunnels that have long optical paths through turbulent media. (2) The common-path design uses fewer optical components than double path designs, making alignment much easier, as well as reducing cost, size, and weight, especially for large setups. [13] (3) While the accuracy of a double path design is dependent on the precision with which the reference element is figured, careful design enables the generated reference beam of the PDI to be of guaranteed precision. [14] A disadvantage is that the amount of light getting through the pinhole depends on how well the light can be focused onto the pinhole. If the incident wavefront is severely aberrated, very little light may get through. [15] The PDI has seen use in various adaptive optics applications. [16] [17]

Lateral shearing

Lateral shearing interferometry is a self-referencing method of wavefront sensing. Instead of comparing a wavefront with a separate path reference wavefront, lateral shearing interferometry interferes a wavefront with a shifted version of itself. As a result, it is sensitive to the slope of a wavefront, not the wavefront shape per se. The illustrated plane parallel plate interferometer has unequal path lengths for the test and reference beams; because of this, it must be used with highly monochromatic (laser) light. It is normally used without any coating on either surface, so as to minimize ghost reflections. An aberrated wavefront from a lens under test is reflected from the front and back of the plate to form the interference pattern. Variations on this basic design allow testing of mirrors. Other forms of lateral shearing interferometer, based on the Jamin, Michelson, Mach–Zehnder, and other interferometer designs, have compensated paths and may be used with white light. [18] Besides optical testing, applications of lateral shearing interferometry have included thin film analysis, mass and thermal diffusion in transparent materials, refractive index and gradient of refractive index measurement, collimation testing, and adaptive optics. [19] [20] Shearing interferometers, a general framework which includes the lateral shearing, Hartmann, Shack–Hartmann, rotational shearing, folding shearing, and aperture masking interferometers, are used in most of the wavefront sensors industrially developed. [21]

Fresnel's biprism

Figure 3. Biprism used in an electron holography system Off axis in TEM.jpg
Figure 3. Biprism used in an electron holography system

From the modern perspective, the result of Young's double slit experiment (see Fig. 2) clearly points towards the wave nature of light, but such was not the case in the early 1800s. Newton, after all, had observed what are now recognized as diffraction phenomena, and wrote on them in his Third Book of Optics, [22] interpreting them in terms of his corpuscular theory of light. Young's contemporaries raised objections that his results could simply represent diffraction effects from the edges of the slits, no different in principle than the fringes that Newton had previously observed. Augustin Fresnel, who supported the wave theory, performed a series of experiments to demonstrate interference effects that could not be simply explained away as being the result of edge diffraction. The most notable of these was his use of a biprism to create two virtual interfering sources by refraction.

An electron version of the Fresnel biprism is used in electron holography, an imaging technique that photographically records the electron interference pattern of an object. The hologram can then be illuminated by a laser resulting in a greatly magnified image of the original object, although the current preference is for numerical reconstruction of the holograms. [23] This technique was developed to enable greater resolution in electron microscopy than is possible using conventional imaging techniques. The resolution of conventional electron microscopy is not limited by electron wavelength, but by the large aberrations of electron lenses. [24]

Fig. 3 shows the basic arrangement of an interference electron microscope. The electron biprism consists of a fine, positively charged electric filament (represented as a dot in the figure) bracketed by two plate electrodes at ground potential. The filament, generally not more than 1 μm in diameter, is usually a gold-coated quartz fiber. By placing the specimen off-axis in the electron beam, the diffracted specimen wavefront and the reference wavefront combine to create the hologram.

Zero-area Sagnac

The Laser Interferometer Gravitational-Wave Observatory (LIGO) consisted of two 4-km Michelson–Fabry–Pérot interferometers, and operated at a power level of about 100 watts of laser power at the beam splitter. A currently ongoing upgrade to Advanced LIGO will require several kilowatts of laser power, and scientists will need to contend with thermal distortion, frequency variation of the lasers, mirror displacement and thermally induced birefringence.

A variety of competing optical systems are being explored for third generation enhancements beyond Advanced LIGO. One of these competing topologies has been the zero-area Sagnac design. As noted above, Sagnac interferometers are, to first order, insensitive to any static or low-frequency displacement of their optical components, nor are the fringes affected by minor frequency variation in the lasers or birefringence. A zero-area variant of the Sagnac interferometer has been proposed for third generation LIGO. Fig. 1 shows how by directing the light through two loops of opposite sense, an effective area of zero is obtained. This variant of the Sagnac interferometer is hence insensitive to rotation or low frequency drift of its optical components, while maintaining a high sensitivity to transient events of astronomical interest. [25] However, many considerations are involved in the choice of an optical system, and despite the zero-area Sagnac's superiority in certain areas, there is as yet no consensus choice of optical system for third generation LIGO. [26] [27]

Scatterplate

A common path alternative to the Twyman–Green interferometer is the scatterplate interferometer, [28] invented by J.M. Burch in 1953. [29] The Twyman–Green interferometer, a double path interferometer, is a variant of the Michelson interferometer that is commonly used to test the precision of optical surfaces and lenses. [30] [31] Since reference and sample paths are divergent, this form of interferometer is extremely sensitive to vibration and to atmospheric turbulence in the light paths, both of which interfere with the optical measurements. Precision measurements of an optical surface are also extremely dependent on the quality of the auxiliary optics.

Because the scatterplate interferometer is a common-path interferometer, the reference and test paths are automatically matched so that a zero order fringe can be easily obtained even with white light. It is relatively insensitive to vibration and turbulence, and the quality of the auxiliary optics is not as critical as in a Twyman-Green setup. [28] Fringe contrast, however, is lower, and a characteristic hotspot may make the scatterplate interferometer unsuitable for various purposes. A variety of other common-path interferometers useful for optical testing have been described. [15] [32]

Fig. 1 shows the interferometer set up to test a spherical mirror. A scatterplate is set near the center of curvature of the mirror under test. This plate has a pattern of tiny opaque patches which are arranged on the plate with inversion symmetry but which are otherwise random in shape and distribution. (1) A certain fraction of the light passes directly through the scatterplate, is reflected by the mirror, but then is scattered as it encounters the scatterplate for the second time. This direct-scattered light forms the reference beam. (2) A certain fraction of the light is scattered as it passes through the scatterplate, is reflected by the mirror, but then passes directly through the scatterplate as it encounters the scatterplate for the second time. This scattered-direct light forms the test beam, which combines with the reference beam to form interference fringes. (3) A certain fraction of the light passes directly through the scatterplate on both of its encounters. This direct-direct light generates a small, undesirable hotspot. (4) A certain fraction of the light is scattered on both encounters with the scatterplate. This scattered-scattered light lowers the overall contrast of the interference pattern. [33]

Figure 4. Bath Interferometer Bath Interferometer CAD model.png
Figure 4. Bath Interferometer

Bath Interferometer

The Bath Interferometer (Fig. 4) can be used to test telescope mirrors. It usually consists of a beam splitter, an optical flat, a biconvex diverger of short focal length and a light source such as a semiconductor laser. [34]

Other configurations

Other common-path interferometer configurations have been described in the literature, such as the double-focus interferometer and the Saunders's prism interferometer, [15] and many others. Common-path interferometers have proven useful in a wide variety of applications including optical coherence tomography, [1] digital holography, [35] and the measurement of phase delays. [36] Their relative resilience to environmental vibration is a common outstanding feature, and they can sometimes be used when no reference beam is available; however, depending on their topology, their interference patterns may be more complicated to interpret than those generated by double path interferometers.

See also

Related Research Articles

<span class="mw-page-title-main">Holography</span> Recording to reproduce a three-dimensional light field

Holography is a technique that enables a wavefront to be recorded and later reconstructed. It is best known as a method of generating real three-dimensional images, but also has a wide range of other applications. In principle, it is possible to make a hologram for any type of wave.

<span class="mw-page-title-main">Interferometry</span> Measurement method using interference of waves

Interferometry is a technique which uses the interference of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy, quantum mechanics, nuclear and particle physics, plasma physics, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms.

In physics, coherence expresses the potential for two waves to interfere. Two monochromatic beams from a single source always interfere. Physical sources are not strictly monochromatic: they may be partly coherent. Beams from different sources are mutually incoherent.

<span class="mw-page-title-main">Mach–Zehnder interferometer</span> Device to determine relative phase shift

The Mach–Zehnder interferometer is a device used to determine the relative phase shift variations between two collimated beams derived by splitting light from a single source. The interferometer has been used, among other things, to measure phase shifts between the two beams caused by a sample or a change in length of one of the paths. The apparatus is named after the physicists Ludwig Mach and Ludwig Zehnder; Zehnder's proposal in an 1891 article was refined by Mach in an 1892 article. Demonstrations of Mach–Zehnder interferometry with particles other than photons had been demonstrated as well in multiple experiments.

<span class="mw-page-title-main">Michelson interferometer</span> Common configuration for optical interferometry

The Michelson interferometer is a common configuration for optical interferometry and was invented by the 19/20th-century American physicist Albert Abraham Michelson. Using a beam splitter, a light source is split into two arms. Each of those light beams is reflected back toward the beamsplitter which then combines their amplitudes using the superposition principle. The resulting interference pattern that is not directed back toward the source is typically directed to some type of photoelectric detector or camera. For different applications of the interferometer, the two light paths can be with different lengths or incorporate optical elements or even materials under test.

<span class="mw-page-title-main">Wavefront</span> Locus of points at equal phase in a wave

In physics, the wavefront of a time-varying wave field is the set (locus) of all points having the same phase. The term is generally meaningful only for fields that, at each point, vary sinusoidally in time with a single temporal frequency.

<span class="mw-page-title-main">Sagnac effect</span> Relativistic effect due to rotation

The Sagnac effect, also called Sagnac interference, named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. The Sagnac effect manifests itself in a setup called a ring interferometer or Sagnac interferometer. A beam of light is split and the two beams are made to follow the same path but in opposite directions. On return to the point of entry the two light beams are allowed to exit the ring and undergo interference. The relative phases of the two exiting beams, and thus the position of the interference fringes, are shifted according to the angular velocity of the apparatus. In other words, when the interferometer is at rest with respect to a nonrotating frame, the light takes the same amount of time to traverse the ring in either direction. However, when the interferometer system is spun, one beam of light has a longer path to travel than the other in order to complete one circuit of the mechanical frame, and so takes longer, resulting in a phase difference between the two beams. Georges Sagnac set up this experiment in 1913 in an attempt to prove the existence of the aether that Einstein's theory of special relativity makes superfluous.

An atom interferometer is an interferometer which uses the wave character of atoms. Similar to optical interferometers, atom interferometers measure the difference in phase between atomic matter waves along different paths. Today, atomic interference is typically controlled with laser beams. Atom interferometers have many uses in fundamental physics including measurements of the gravitational constant, the fine-structure constant, the universality of free fall, and have been proposed as a method to detect gravitational waves. They also have applied uses as accelerometers, rotation sensors, and gravity gradiometers.

<span class="mw-page-title-main">Fibre-optic gyroscope</span>

A fibre-optic gyroscope (FOG) senses changes in orientation using the Sagnac effect, thus performing the function of a mechanical gyroscope. However its principle of operation is instead based on the interference of light which has passed through a coil of optical fibre, which can be as long as 5 kilometres (3 mi).

<span class="mw-page-title-main">Shearing interferometer</span>

The shearing interferometer is an extremely simple means to observe interference and to use this phenomenon to test the collimation of light beams, especially from laser sources which have a coherence length which is usually significantly longer than the thickness of the shear plate so that the basic condition for interference is fulfilled.

Lloyd's mirror is an optics experiment that was first described in 1834 by Humphrey Lloyd in the Transactions of the Royal Irish Academy. Its original goal was to provide further evidence for the wave nature of light, beyond those provided by Thomas Young and Augustin-Jean Fresnel. In the experiment, light from a monochromatic slit source reflects from a glass surface at a small angle and appears to come from a virtual source as a result. The reflected light interferes with the direct light from the source, forming interference fringes. It is the optical wave analogue to a sea interferometer.

Holographic interferometry (HI) is a technique which enables static and dynamic displacements of objects with optically rough surfaces to be measured to optical interferometric precision. These measurements can be applied to stress, strain and vibration analysis, as well as to non-destructive testing and radiation dosimetry. It can also be used to detect optical path length variations in transparent media, which enables, for example, fluid flow to be visualised and analyzed. It can also be used to generate contours representing the form of the surface.

<span class="mw-page-title-main">Fizeau interferometer</span>

A Fizeau interferometer is an interferometric arrangement whereby two reflecting surfaces are placed facing each other. As seen in Fig 1, the rear-surface reflected light from the transparent first reflector is combined with front-surface reflected light from the second reflector to form interference fringes.

<span class="mw-page-title-main">Point diffraction interferometer</span>

A point diffraction interferometer (PDI) is a type of common-path interferometer. Unlike an amplitude-splitting interferometer, such as a Michelson interferometer, which separates out an unaberrated beam and interferes this with the test beam, a common-path interferometer generates its own reference beam. In PDI systems, the test and reference beams travel the same or almost the same path. This design makes the PDI extremely useful when environmental isolation is not possible or a reduction in the number of precision optics is required. The reference beam is created from a portion of the test beam by diffraction from a small pinhole in a semitransparent coating. The principle of a PDI is shown in Figure 1.

The N-slit interferometer is an extension of the double-slit interferometer also known as Young's double-slit interferometer. One of the first known uses of N-slit arrays in optics was illustrated by Newton. In the first part of the twentieth century, Michelson described various cases of N-slit diffraction.

<span class="mw-page-title-main">White light scanner</span>

A white light scanner (WLS) is a device for performing surface height measurements of an object using coherence scanning interferometry (CSI) with spectrally-broadband, "white light" illumination. Different configurations of scanning interferometer may be used to measure macroscopic objects with surface profiles measuring in the centimeter range, to microscopic objects with surface profiles measuring in the micrometer range. For large-scale non-interferometric measurement systems, see structured-light 3D scanner.

Length measurement, distance measurement, or range measurement (ranging) refers to the many ways in which length, distance, or range can be measured. The most commonly used approaches are the rulers, followed by transit-time methods and the interferometer methods based upon the speed of light.

<span class="mw-page-title-main">White light interferometry</span> Measurement technique

As described here, white light interferometry is a non-contact optical method for surface height measurement on 3D structures with surface profiles varying between tens of nanometers and a few centimeters. It is often used as an alternative name for coherence scanning interferometry in the context of areal surface topography instrumentation that relies on spectrally-broadband, visible-wavelength light.

Alexey Okulov is a Soviet and Russian physicist, the author of pioneering works in laser physics and theoretical physics.

References

  1. 1 2 Vakhtin, A. B.; Kane, D. J.; Wood, W. R.; Peterson, K. A. (2003). "Common-path interferometer for frequency-domain optical coherence tomography" (PDF). Applied Optics. 42 (34): 6953–6957. Bibcode:2003ApOpt..42.6953V. doi:10.1364/AO.42.006953. PMID   14661810 . Retrieved 29 March 2012.
  2. ↑ Lin, Jiun-You; Chen, Kun-Huang; Chen, Jing-Heng (2011-07-01). "Measurement of small displacement based on surface plasmon resonance heterodyne interferometry". Optics and Lasers in Engineering. 49 (7): 811–815. Bibcode:2011OptLE..49..811L. doi:10.1016/j.optlaseng.2011.03.005. ISSN   0143-8166.
  3. ↑ Ng, Siu Pang; Loo, Fong Chuen; Wu, Shu Yuen; Kong, Siu Kai; Wu, Chi Man Lawrence; Ho, Ho Pui (2013-08-26). "Common-path spectral interferometry with temporal carrier for highly sensitive surface plasmon resonance sensing". Optics Express. 21 (17): 20268–20273. Bibcode:2013OExpr..2120268N. doi: 10.1364/OE.21.020268 . ISSN   1094-4087. PMID   24105572.
  4. ↑ "The Sagnac Interferometer" (PDF). University of Arizona College of Optical Sciences. Retrieved 30 March 2012.[ permanent dead link ]
  5. ↑ Hariharan, P. (2007). Basics of Interferometry, 2nd edition. Elsevier. p. 19. ISBN   978-0-12-373589-8.
  6. 1 2 Anderson, R.; Bilger, H. R.; Stedman, G. E. (1994). ""Sagnac effect" A century of Earth-rotated interferometers" (PDF). Am. J. Phys. 62 (11): 975–985. Bibcode:1994AmJPh..62..975A. doi:10.1119/1.17656 . Retrieved 30 March 2012.
  7. ↑ Lin, S. C.; Giallorenzi, T. G. (1979). "Sensitivity analysis of the Sagnac-effect optical-fiber ring interferometer". Applied Optics. 18 (6): 915–931. Bibcode:1979ApOpt..18..915L. doi:10.1364/AO.18.000915. PMID   20208844.
  8. ↑ Michelson, A. A.; Morley, E. W. (1886). "Influence of Motion of the Medium on the Velocity of Light". Am. J. Sci. 31 (185): 377–386. Bibcode:1886AmJS...31..377M. doi:10.2475/ajs.s3-31.185.377. S2CID   131116577.
  9. ↑ G. W. Hammar (1935). "The Velocity of Light Within a Massive Enclosure". Physical Review . 48 (5): 462–463. Bibcode:1935PhRv...48..462H. doi:10.1103/PhysRev.48.462.2.
  10. ↑ H. P. Robertson; Thomas W. Noonan (1968). "Hammar's experiment". Relativity and Cosmology . Philadelphia: Saunders. pp.  36–38.
  11. ↑ Millerd, J. E.; Brock, N. J.; Hayes, J. B.; Wyant, J. C. (2004). Creath, Katherine; Schmit, Joanna (eds.). "Instantaneous phase-shift, point-diffraction interferometer" (PDF). Proceedings of SPIE. Interferometry XII: Techniques and Analysis. 5531: 264–272. Bibcode:2004SPIE.5531..264M. doi:10.1117/12.560959. S2CID   125388913. Archived from the original (PDF) on 8 October 2010. Retrieved 31 March 2012.
  12. ↑ Mercer, C. R.; Rashidnia, N.; Creath, K. (1996). "High data density temperature measurement for quasi steady-state flows" (PDF). Experiments in Fluids. 21 (1): 11–16. Bibcode:1996ExFl...21...11M. doi:10.1007/BF00204630. hdl: 2060/19960033183 . S2CID   55927553 . Retrieved 31 March 2012.
  13. ↑ Ferraro, P.; Paturzo, M.; Grilli, S. (2007). "Optical wavefront measurement using a novel phase-shifting point-diffraction interferometer". SPIE. Retrieved 26 May 2012.{{cite web}}: CS1 maint: multiple names: authors list (link)
  14. ↑ Naulleau, P. P.; Goldberg, K. A.; Lee, S. H.; Chang, C.; Attwood, D.; Bokor, J. (1999). "Extreme-ultraviolet phase-shifting point-diffraction interferometer: A wave-front metrology tool with subangstrom reference-wave accuracy". Applied Optics. 38 (35): 7252–7263. Bibcode:1999ApOpt..38.7252N. doi:10.1364/AO.38.007252. PMID   18324274.
  15. 1 2 3 Mallick, S.; Malacara, D. (2007). "Common-Path Interferometers". Optical Shop Testing. p. 97. doi:10.1002/9780470135976.ch3. ISBN   9780470135976.
  16. ↑ Love, G. D.; Andrews, N.; Birch, P.; Buscher, D.; Doel, P.; Dunlop, C.; Major, J.; Myers, R.; Purvis, A.; Sharples, R.; Vick, A.; Zadrozny, A.; Restaino, S. R.; Glindemann, A. (1995). "Binary adaptive optics: atmospheric wave-front correction with a half-wave phase shifter" (PDF). Applied Optics. 34 (27): 6058–6066. Bibcode:1995ApOpt..34.6058L. doi:10.1364/AO.34.006058. PMID   21060444. Archived from the original (PDF) on 7 November 2012. Retrieved 31 March 2012.
  17. ↑ Paterson, C.; Notaras, J. (2007). "Demonstration of closed-loop adaptive optics with a point-diffraction interferometer in strong scintillation with optical vortices". Optics Express. 15 (21): 13745–13756. Bibcode:2007OExpr..1513745P. doi: 10.1364/OE.15.013745 . PMID   19550645.
  18. ↑ Strojnik, M.; Paez, G.; Mantravadi, M. (2007). "Lateral Shear Interferometers". Optical Shop Testing. p. 122. doi:10.1002/9780470135976.ch4. ISBN   9780470135976.
  19. ↑ Chanteloup, J. C. (2005). "Multiple-wave lateral shearing interferometry for wave-front sensing". Applied Optics. 44 (9): 1559–1571. Bibcode:2005ApOpt..44.1559C. doi:10.1364/AO.44.001559. PMID   15818859.
  20. ↑ Ribak, E.N. "Interferometry following adaptive optics" (PDF). Archived from the original (PDF) on 25 February 2013. Retrieved 14 April 2012.
  21. ↑ Primot, J.; Guernineau, N. "Shearing interferometry for wavefront sensing" (PDF). OpSciTech. Archived from the original (PDF) on 2012-03-03. Retrieved 2012-04-15.{{cite web}}: CS1 maint: multiple names: authors list (link)
  22. ↑ Newton, Isaac (1730). Opticks: or, a Treatise of the Reflections, Refractions, Inflections and Colours of Light. Project Gutenberg. pp. 317–406.
  23. ↑ M. Lehmann, H. Lichte, Tutorial on off-axis electron holography, Microsc. Microanal. 8(6), 447–466 (2002)
  24. ↑ Tonomura, A. (1999). Electron Holography, 2nd ed. Springer. ISBN   3540645551.
  25. ↑ Sun, K.-X.; Fejer, M. M.; Gustafson, E.; Byer R. L. (1996). "Sagnac Interferometer for Gravitational-Wave Detection" (PDF). Physical Review Letters. 76 (17): 3053–3056. Bibcode:1996PhRvL..76.3053S. doi:10.1103/PhysRevLett.76.3053. PMID   10060864 . Retrieved 31 March 2012.
  26. ↑ Freise, A.; Chelkowski, S.; Hild, S.; Pozzo, W. D.; Perreca, A.; Vecchio, A. (2009). "Triple Michelson interferometer for a third-generation gravitational wave detector". Classical and Quantum Gravity. 26 (8): 085012. arXiv: 0804.1036 . Bibcode:2009CQGra..26h5012F. doi:10.1088/0264-9381/26/8/085012. S2CID   7535227.
  27. ↑ Eberle, T.; Steinlechner, S.; Bauchrowitz, J. R.; Händchen, V.; Vahlbruch, H.; Mehmet, M.; Müller-Ebhardt, H.; Schnabel, R. (2010). "Quantum Enhancement of the Zero-Area Sagnac Interferometer Topology for Gravitational Wave Detection". Physical Review Letters. 104 (25): 251102. arXiv: 1007.0574 . Bibcode:2010PhRvL.104y1102E. doi:10.1103/PhysRevLett.104.251102. PMID   20867358. S2CID   9929939.
  28. 1 2 "Testing Curved Surfaces and Lenses" (PDF). University of Arizona College of Optical Sciences. Archived from the original (PDF) on 25 July 2010. Retrieved 30 March 2012.
  29. ↑ Burch, J. M. (1953). "Scatter fringes of equal thickness". Nature. 171 (4359): 889–890. Bibcode:1953Natur.171..889B. doi:10.1038/171889a0. S2CID   24650839.
  30. ↑ "Twyman-Green Interferometer". SPIE. Retrieved 30 March 2012.
  31. ↑ "Twyman-Green Interferometer". Optics 4 Engineers. Retrieved 30 March 2012.
  32. ↑ Dyson, J. (1957). "Common-Path Interferometer for Testing Purposes". Journal of the Optical Society of America. 47 (5): 386–387. Bibcode:1957JOSA...47..386D. doi:10.1364/josa.47.000386.
  33. ↑ Wyant, J.C. (2002). "White Light Interferometry" (PDF). Proceedings of SPIE. 4737: 98–107. Bibcode:2002SPIE.4737...98W. doi:10.1117/12.474947. S2CID   123532345. Archived from the original (PDF) on 6 September 2006. Retrieved 30 March 2012.
  34. ↑ DEpatent 2300958,Karl-Ludwig Bath,"Ein Interferometer mit gemeinsamem Weg für Referenzstrahl und messtrahl (common path interferometer)",published 1974-07-01
  35. ↑ Mico, V.; Zalefsky, Z; Garcia, J. (2006). "Superresolution optical system by common-path interferometry" (PDF). Optics Express. 14 (12): 5168–5177. Bibcode:2006OExpr..14.5168M. doi: 10.1364/oe.14.005168 . PMID   19516681 . Retrieved 31 March 2012.
  36. ↑ Márquez, A. S.; Yamauchi, M.; Davis, J. A.; Franich, D. J. (2001). "Phase measurements of a twisted nematic liquid crystal spatial light modulator with a common-path interferometer". Optics Communications. 190 (1–6): 129–133. Bibcode:2001OptCo.190..129M. doi:10.1016/S0030-4018(01)01091-4.
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