OSA's Digital Library

Journal of the Optical Society of America A

Journal of the Optical Society of America A

| OPTICS, IMAGE SCIENCE, AND VISION

  • Vol. 18, Iss. 3 — Mar. 1, 2001
  • pp: 696–703

Measurements of the instantaneous velocity difference and the local velocity with a fiber-optic coupler

Sheng-Hong Yao, Viktor K. Horváth, Penger Tong, Bruce J. Ackerson, and Walter I. Goldburg  »View Author Affiliations


JOSA A, Vol. 18, Issue 3, pp. 696-703 (2001)
http://dx.doi.org/10.1364/JOSAA.18.000696


View Full Text Article

Enhanced HTML    Acrobat PDF (382 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

New optical arrangements with two single-mode input fibers and a fiber-optic coupler are devised to measure the instantaneous velocity difference and the local velocity. The fibers and the coupler are polarization-preserving to guarantee a high signal-to-noise ratio. When the two input fibers are used to collect the scattered light with the same momentum-transfer vector but from two spatially separated regions in a flow, the obtained signals interfere when combined via the fiber-optic coupler. The resultant light received by a photomultiplier tube contains a cross-beat frequency proportional to the velocity difference between the two measuring points. If the two input fibers are used to collect the scattered light from a common scattering region but with two different momentum-transfer vectors, then the resultant light contains a self-beat frequency proportional to the local velocity at the measuring point. The experiment shows that both the cross-beat and the self-beat signals are large and that the standard laser Doppler signal processor can be used to measure the velocity difference and the local velocity in real time. The new technique will have various applications in the general area of fluid dynamics.

© 2001 Optical Society of America

OCIS Codes
(030.7060) Coherence and statistical optics : Turbulence
(060.1810) Fiber optics and optical communications : Buffers, couplers, routers, switches, and multiplexers
(060.2420) Fiber optics and optical communications : Fibers, polarization-maintaining
(120.7250) Instrumentation, measurement, and metrology : Velocimetry

History
Original Manuscript: June 5, 2000
Revised Manuscript: September 28, 2000
Manuscript Accepted: September 28, 2000
Published: March 1, 2001

Citation
Sheng-Hong Yao, Viktor K. Horváth, Penger Tong, Bruce J. Ackerson, and Walter I. Goldburg, "Measurements of the instantaneous velocity difference and the local velocity with a fiber-optic coupler," J. Opt. Soc. Am. A 18, 696-703 (2001)
http://www.opticsinfobase.org/josaa/abstract.cfm?URI=josaa-18-3-696

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited