Laser Science Laboratory, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya, 468-8511, Japan.
Graduate School of Engineering College of Design and Manufacturing Technology, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido, 050-8585, Japan.
Nat Commun. 2023 Jul 4;14(1):3929. doi: 10.1038/s41467-023-39628-6.
Mid-infrared spectroscopy probes molecular vibrations to identify chemical species and functional groups. Therefore, mid-infrared hyperspectral imaging is one of the most powerful and promising candidates for chemical imaging using optical methods. Yet high-speed and entire bandwidth mid-infrared hyperspectral imaging has not been realized. Here we report a mid-infrared hyperspectral chemical imaging technique that uses chirped pulse upconversion of sub-cycle pulses at the image plane. This technique offers a lateral resolution of 15 µm, and the field of view is adjustable between 800 µm × 600 µm to 12 mm × 9 mm. The hyperspectral imaging produces a 640 × 480 pixel image in 8 s, which covers a spectral range of 640-3015 cm, comprising 1069 wavelength points and offering a wavenumber resolution of 2.6-3.7 cm. For discrete frequency mid-infrared imaging, the measurement speed reaches a frame rate of 5 kHz, the repetition rate of the laser. As a demonstration, we effectively identified and mapped different components in a microfluidic device, plant cell, and mouse embryo section. The great capacity and latent force of this technique in chemical imaging promise to be applied to many fields such as chemical analysis, biology, and medicine.
中红外光谱通过探测分子振动来识别化学物质和官能团。因此,中红外高光谱成像是使用光学方法进行化学成像的最强大、最有前途的候选技术之一。然而,高速和整个带宽的中红外高光谱成像是尚未实现的。在这里,我们报告了一种中红外高光谱化学成像技术,该技术使用在像平面上的啁啾脉冲上转换亚周期脉冲。该技术具有 15μm 的横向分辨率,视场可在 800μm×600μm 至 12mm×9mm 之间调节。高光谱成像在 8s 内生成一个 640×480 像素的图像,覆盖 640-3015cm 的光谱范围,包含 1069 个波长点,波数分辨率为 2.6-3.7cm。对于离散频率的中红外成像,测量速度达到 5kHz 的帧速率,即激光的重复率。作为演示,我们有效地识别和绘制了微流控器件、植物细胞和小鼠胚胎切片中的不同成分。这项技术在化学成像中的巨大潜力有望应用于化学分析、生物学和医学等多个领域。