444:
of light using an ultrasonic grating was first observed by Debye and Sears in 1932. When ultrasonic waves are propagated in a liquid, the density varies from layer to layer due to periodic variation of pressure. This grating can determine the wavelength of monochromatic light and the speed of waves.
94:
The diffraction grating formed in this way is analogous to a conventional diffraction grating with lines ruled on a glass plate. The less dense antinodes refract light less and are analogous to the transmitting slits of a conventional grating. The denser nodes refract light more and are analogous
74:
When ultrasonic waves are generated in a liquid in a rectangular vessel, the wave can be reflected from the walls of the vessel. These reflected waves are called echoes. The direct and reflected waves are superimposed, forming a
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628:
if the other is known. We need not worry about the grating element since the nodes themselves act as slits, hence the distance between two slits are equal to the ultrasonic wave wavelength.
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This method determines the velocity of ultrasonic waves using monochromatic sources like sodium vapour lamps. The medium is usually a piezoelectric crystal such as
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125:
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method determines the wavelength of monochromatic light using an acoustic or ultrasonic gratings. This method utilises the concept of
28:
831:
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is the velocity of the ultrasonic wave in the liquid we can calculate the velocity of the wave with:
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is the wavelength of the ultrasonic waves, then applying the principle of diffraction, we get
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36:
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oscillator. By adjusting the frequency of the oscillator, we can determine the velocity
844:
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110:
84:
873:
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to a parallel beam of light passed through the liquid at right angles to the wave.
766:
Kinoshita, S.; Yoshioka, S.; Miyazaki, J. (2008). "Physics of structural colors".
441:
426:
46:
An ultrasonic wave is a sound wave at a frequency greater than 20 kHz. The
35:
in a medium, which alters the physical properties of the medium (and hence the
636:
148:
104:
822:
Robert
Lagemann, "The optical diffraction method", in Dudley Williams (ed),
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47:
643:. A mechanical stress is produced along an axis of the crystal using an
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is a more general term that includes operation at audible frequencies.
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is more than the density at an antinode. Hence, the liquid acts as a
147:
is the wavelength of the light passed through the grating that is
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51:
16:
Diffraction grating produced by interfering ultrasonic waves
644:
807:
Philip McCord Morse, "Light scattering by a sound beam",
470:
is the wavelength of a monochromatic light source, and
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cannot recognize ultrasonic waves, but animals such as
542:{\displaystyle \lambda _{c}\sin \theta =n\lambda \,\!}
811:, pp. 809–816, Princeton University Press, 1986
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171:, then the nth order of the maximum is given by:
95:to the opaque part of a conventional grating.
331:{\displaystyle v/\nu =n\lambda /\sin \theta }
58:can. Ultrasonic waves can be produced by the
8:
383:{\displaystyle v=\nu n\lambda /\sin \theta }
717:{\displaystyle v_{c}=\eta \lambda _{c}\,\!}
826:, pp. 702–703, Academic Press, 1961
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254:{\displaystyle d=n\lambda /\sin \theta }
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205:{\displaystyle d\sin \theta =n\lambda }
7:
749:is the frequency of the oscillator.
103:The grating element is equal to the
39:) in a grid-like pattern. The term
107:of the ultrasonic waves—denoted by
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676:of the ultrasonic waves by using
621:{\displaystyle \lambda _{c}\,\!}
492:{\displaystyle \lambda _{c}\,\!}
768:Reports on Progress in Physics
1:
788:10.1088/0034-4885/71/7/076401
577:Thus we can calculate either
574:is the angle of diffraction.
860:Acousto-optical spectrometer
592:{\displaystyle \lambda \,\!}
463:{\displaystyle \lambda \,\!}
567:{\displaystyle \theta \,\!}
896:
742:{\displaystyle \eta \,\!}
669:{\displaystyle v_{c}\,\!}
140:{\displaystyle \lambda }
855:Acousto-optic deflector
850:Acousto-optic modulator
164:{\displaystyle \theta }
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809:Theoretical Acoustics
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437:to obtain a grating.
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406:{\displaystyle \nu }
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60:piezoelectric effect
780:2008RPPh...71g6401K
89:diffraction grating
83:of the liquid at a
25:diffraction grating
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440:The phenomenon of
421:Debye–Sears method
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21:ultrasonic grating
824:Molecular Physics
277:{\displaystyle v}
120:{\displaystyle d}
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865:Nonlinear optics
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64:magnetostriction
41:acoustic grating
37:refractive index
33:ultrasonic waves
27:produced by the
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845:Acousto-optics
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774:(7): 076401.
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641:Rochelle salt
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77:standing wave
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23:is a type of
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151:by an angle
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29:interference
20:
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880:Diffraction
442:diffraction
99:Mathematics
832:0080859763
817:0691024014
753:References
637:tourmaline
149:diffracted
105:wavelength
735:η
704:λ
700:η
608:λ
585:λ
560:θ
535:λ
526:θ
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511:λ
479:λ
456:λ
415:frequency
401:ν
378:θ
375:
364:λ
358:ν
326:θ
323:
312:λ
303:ν
249:θ
246:
235:λ
200:λ
191:θ
188:
159:θ
135:λ
70:Mechanism
48:human ear
874:Category
839:See also
796:53068819
776:Bibcode
413:is the
81:density
79:. The
830:
815:
794:
727:where
633:quartz
552:Where
393:where
792:S2CID
639:, or
431:Sears
427:Debye
127:. If
828:ISBN
813:ISBN
425:The
341:or,
85:node
62:and
56:dogs
54:and
52:bats
784:doi
599:or
520:sin
448:If
372:sin
320:sin
264:If
243:sin
215:or
185:sin
31:of
19:An
876::
790:.
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772:71
770:.
645:RF
635:,
66:.
834:.
819:.
798:.
786::
778::
708:c
697:=
692:c
688:v
660:c
656:v
612:c
532:n
529:=
515:c
483:c
429:–
368:/
361:n
355:=
352:v
316:/
309:n
306:=
299:/
295:v
272:v
239:/
232:n
229:=
226:d
197:n
194:=
182:d
115:d
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