Optical sensing of sound fields: Non-contact, quantitative, and single-shot imaging of sound using high-speed polarization camera

Kenji Ishikawa, Kohei Yatabe, Yusuke Ikeda, Yasuhiro Oikawa, Takashi Onuma, Hayato Niwa, Minoru Yoshii

    Research output: Contribution to journalConference article

    9 Citations (Scopus)


    Imaging of a sound field aids understanding of the actual behavior of the field. That is useful for obtaining acoustical spatial characteristics of transducers, materials and noise sources. For high spatial resolution imaging, optical measurement methods have been used thanks to its contactless nature. This paper presents sound field imaging method based on parallel phase-shifting interferometry, which enables to acquire an instantaneous two-dimensional phase distribution of light. Information of sound field is calculated from the phase of light based on the acousto-optic theory. The system consists of a polarization interferometer and high-speed polarization camera. The number of the measurement points in a single image are 512 × 512 and the interval between adjacent pixels is 0.22 mm. Therefore, the system can image a sound field with much higher spatial resolution compared with conventional imaging methods such as microphone arrays. The maximum frame rate, which is corresponding to the sampling frequency, is 1.55 M frames per second. This paper contains the principle of optical measurement of sound, the description of the system, and several experimental results including imaging of sound fields generated by transducers and reflection of the sound waves.

    Original languageEnglish
    Article number030005
    JournalProceedings of Meetings on Acoustics
    Issue number1
    Publication statusPublished - 2016 Nov 28
    Event172nd Meeting of the Acoustical Society of America - Honolulu, United States
    Duration: 2016 Nov 282016 Dec 2


    ASJC Scopus subject areas

    • Acoustics and Ultrasonics

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