Imaging of sound aids the understanding of the acoustical phenomena such as propagation,
reflection, and diffraction, which is strongly required for various acoustical applications. The …

In this Letter, simultaneous imaging of flow and sound by using parallel phase-shifting
interferometry and a high-speed polarization camera is proposed. The proposed method …

The internal ultrasonic field of an acousto-optic crystal determines the effects of acousto-
optic modulator (AOM) devices. Conventionally, schlieren method is used for the …

For the visualization of a sound field, a widely used method is the superimposition of the
sound information onto a camera view. Although it effectively enables the understanding the …

A midfringe locked interferometer with differential detection is proposed for non-contact
optical sound measurement, and the equivalent noise level of approximately 0 dB SPL/Hz is …

This paper presents a method of significantly improving the previously proposed simple,
flexible, and accurate phase retrieval algorithm for the random phase-shifting interferometry …

As an alternative to microphones, optical techniques have been studied for measuring a
sound field. They enable contactless and non-invasive acoustical observation by detecting …

Sound field imaging techniques have been found very useful for acoustic designs. Building
on this idea, innovative techniques are needed and presented in this paper, where we report …

Measurement of surface shape and refractive index for moving transparent objects is critical
in various fields. A parallel phase-shifting digital holography system that can record and …

Sound fields radiated from the castanet, a Spanish percussive instrument comprising two
shells, were optically visualized. A measurement system, which used parallel phase-shifting …