Scanning differential optical profilometer for simultaneous measurement of amplitude and phase variation

C. W. See, R. K. Appel, Michael Geoffrey Somekh

Research output: Journal article publicationJournal articleAcademic researchpeer-review

36 Citations (Scopus)


A scanning optical profilometer is described which can simultaneously and independently measure the differential phase/amplitude variation of light reflected off an object surface. This information may then be interpreted as topographical and reflectivity variation of the object surface. The system is based on a heterodyne interferometer and uses two beams to probe the surface. The theoretical sensitivity of the system is 3×10-3mrad in phase and 3 in 105in reflectivity variation, both measured in a 1 kHz bandwidth. Preliminary measurements of film thickness and reflectivity variation are presented. This system also has potential applications for imaging objects with minute structural variations.
Original languageEnglish
Pages (from-to)10-12
Number of pages3
JournalApplied Physics Letters
Issue number1
Publication statusPublished - 1 Dec 1988
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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