Wavelength dependent damage in biological multi-photon confocal microscopy:: A micro-spectroscopic comparison between femtosecond Ti:sapphire and Cr:forsterite laser sources
Wavelength dependent damage in biological multi-photon confocal microscopy:: A micro-spectroscopic comparison between femtosecond Ti:sapphire and Cr:forsterite laser sources
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DOI：
10.1023/a:1021303426482
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发表时间：
2002-12-01
影响因子：
3
通讯作者：
Lin, BL
中科院分区：
文献类型：
--
作者：
Chen, IH;Chu, SW;Lin, BL
通过同时吸收两个光子的分子激发在激光扫描荧光显微镜中提供了固有的三维分辨率。因此，诱导的双光子吸收和伴随的多光子吸收/电离不仅会导致光漂白，而且还会导致焦点附近的细胞损伤。本文研究了高强度飞秒近红外激光对细胞损伤的波长依赖性。该研究使用钛：蓝宝石激光器和铬：镁橄榄石激光器进行。随着Cr：镁橄榄石激光器的输出波长的延长，多光子吸收和自发荧光被发现被显著抑制，并且破坏性等离子体的形成被发现大大减少。在激光平均功率超过100 mW的长期照射下，使用紧密聚焦的铬镁橄榄石激光束，可以在大多数植物标本中观察到持续的多光子光谱。相比之下，多光子吸收诱导的破坏性等离子体的形成，经常观察到与紧密聚焦的钛：蓝宝石激光束在几秒钟内，超过10毫瓦的激光平均功率。
Molecular excitation by the simultaneous absorption of two photons provides intrinsic three-dimensional resolution in laser scanning fluorescence microscopy. Thus induced two-photon absorption and the accompanied multi-photon absorption/ionization not only cause photo-bleaching but also cell damage in the vicinity of the focal point. In this paper, we study the wavelength dependent cell damage induced by high intensity femtosecond near infrared lasers. The study was performed with a Ti: sapphire laser and a Cr: forsterite laser. With a longer output wavelength from a Cr: forsterite laser, multi-photon absorption and auto-fluorescence were found to be significantly suppressed and the destructive plasma formation was found to be greatly reduced. Sustained multi-photon spectra can be observed in most plant specimens with a tightly focused Cr: forsterite laser beam under long term irradiation with more than 100 mW laser average power. In contrast, multi-photon absorption induced destructive plasma formation were frequently observed with a tightly focused Ti: sapphire laser beam within seconds with more than 10 mW laser average power.