Megumi Uchida

No-scanning 3D measurement method using ultrafast dimensional conversion with a chirped optical frequency comb

A simultaneously high-precision, wide-range, and ultrafast time-resolution one-shot 3D shape measurement method is presented. Simultaneous times of flight from multiple positions to a target encoded in a chirped optical frequency comb can be obtained from spectral interferometry. We experimentally demonstrate a one-shot imaging profile measurement of a known step height of 480 µm with µm-level accuracy. We further demonstrate the extension of the dynamic range by measuring in one shot a large step height of 3 m while maintaining high accuracy using the accurate pulse-to-pulse separation of the optical frequency comb. The proposed method with its large dynamic range and measurement versatility can be applied to a broad range of applications, including microscopic structures, objects with large size or aspect ratio, and ultrafast time-resolved imaging. This study provides a powerful and versatile tool for 3D measurement, where various ranges of measurement performances can be tailored to demand.

One-shot three-dimensional measurements with a fiber bundle using a chirped optical frequency comb

We developed a one-shot multi-point three-dimensional (3D)-measurement method using a bundle composed of 55 multi-mode fibers based on ultrafast space-time-frequency conversion with a chirped optical frequency comb. We demonstrated measurement of the 3D profile of a reflective object by one-shot imaging using the fiber bundle with micrometer accuracy.

Non-scanning three-dimensional imaging using two-dimensional spectroscopy and spectral interferometry with a chirped frequency comb

Non-scanning three-dimensional imaging with a chirped-frequency comb is demonstrated using two-dimensional (2D) pulse-to-pulse spectral interferometry and 2D spectroscopy. The profile of a structure of three gauge blocks was measured with μm-level uncertainty.

Non-scanning three-dimensional imaging using spectral interferometry with chirped frequency comb

One-shot 3D imaging-method with a chirped frequency comb was demonstrated using 2D pulse-to-pulse spectral interferometry. A step-height was measured with 6.1-μm-uncertainty, currently limited by the detection system. The method has large dynamic-range with high precision.