Multi-layer surface profiling using gated wavefront sensing

Xin Wang, Nur Daililla Binti Nordin, Eddy Mun Tik Chow, Ching Seong Tan, Kuew Wai Chew, Carmen S Menoni

    Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-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 publicationProceedings of the Optics and Measurement Conference 2014
    EditorsJana Kovacicinova, Tomas Vit
    Place of PublicationWashington USA
    Pages1 - 6
    Number of pages6
    ISBN (Print)9781628415575
    Publication statusPublished - 2015
    EventOptics and Measurement Conference 2014 - Liberec Czech Republic, Washington USA
    Duration: 1 Jan 2015 → …


    ConferenceOptics and Measurement Conference 2014
    CityWashington USA
    Period1/01/15 → …

    Cite this

    Wang, X., Nordin, N. D. B., Chow, E. M. T., Tan, C. S., Chew, K. W., & Menoni, C. S. (2015). Multi-layer surface profiling using gated wavefront sensing. In J. Kovacicinova, & T. Vit (Eds.), Proceedings of the Optics and Measurement Conference 2014 (Vol. 9442, pp. 1 - 6). SPIE.