Parallel detection of low modulation depth signals: Application to picosecond ultrasonics

R. J. Smith, Michael Geoffrey Somekh, S. D. Sharples, M. C. Pitter, I. Harrison, C. Rossignol

Research output: Journal article publicationJournal articleAcademic researchpeer-review

12 Citations (Scopus)

Abstract

We demonstrate parallel detection of laser ultrasonic signals above 50 GHz, where the signals are encoded as small modulations on a large dc background signal. The measurement problem addressed here is generic for many situations, particularly pump/probe experiments, and this paper discusses the problems of moving from single point to parallel detection and practical solutions. This is achieved with a commercial detector array, custom interface electronics and a carefully selected phase stepping algorithm. The parallel detection of Brillouin oscillations illustrates the very low modulation depths that can be measured with this technique. Noise performance and projected improvements for future custom detectors are also considered.
Original languageEnglish
Article number055301
JournalMeasurement Science and Technology
Volume19
Issue number5
DOIs
Publication statusPublished - 1 May 2008
Externally publishedYes

Keywords

  • Arrays
  • Demodulation
  • Optical sensors
  • Ultrasonic measurement

ASJC Scopus subject areas

  • Instrumentation
  • Engineering (miscellaneous)
  • Applied Mathematics

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