Multi-layer surface profiling using gated wavefront sensing

Xin Wang, Nur Dalilla Nordin, Eddy Chow Mun Tik, Chingseong Tan, Kuew Wai Chew, Carmen Menoni

Research output: Chapter in Book/Conference proceedingConference contributionpeer-review


Recently, multi-layer surface profiling and inspection has been considered an emerging topic that can be used to solve various manufacturing inspection problems, such as graded index lenses, TSV (Thru-Silicon Via), and optical coating. In our study, we proposed a gated wavefront sensing approach to estimate the multi-layer surface profile. In this paper, we set up an experimental platform to validate our theoretical models and methods. Our test bed consists of pulse laser, collimator, prism, well-defined focusing lens, testing specimen, and gated wavefront sensing assembly (e.g., lenslet and gated camera). Typical wavefront measurement steps are carried out for the gated system, except the reflectance is timed against its time of flight as well as its intensity profile. By synchronizing the laser pulses to the camera gate time, it is possible to discriminate a multi-layer wavefront from its neighbouring discrete layer reflections.

Original languageEnglish
Title of host publicationOptics and Measurement Conference 2014
EditorsTomas Vit, Jana Kovacicinova
ISBN (Electronic)9781628415575
Publication statusPublished - 2015
Externally publishedYes
EventOptics and Measurement Conference 2014 - Liberec, Czech Republic
Duration: 7 Oct 201410 Oct 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceOptics and Measurement Conference 2014
Country/TerritoryCzech Republic


  • gated wavefront sensing
  • Multi-layer surface profiling

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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