König K, Liang H, Berns M W, Tromberg B J
Opt Lett. 1996 Jul 15;21(14):1090-2. doi: 10.1364/ol.21.001090.
We report on cell damage of single cells confined in continuous-wave (cw), near-infrared (NIR) multimode optical traps as a result of multiphoton absorption phenomena. Trapping beams at NIR wavelengths less than 800 nm are capable of damaging cells through a two-photon absorption process. Cell damage is more pronounced in multimode cw traps compared with single-frequency true cw NIR traps because of transient power enhancement by longitudinal mode beating. Partial mode locking in tunable cw Ti:sapphire lasers used as trapping beam sources can produce unstable subnanosecond pulses at certain wavelengths that amplify multiphoton absorption effects significantly. We recommend the use of single-frequency long-wavelength NIR trapping beams for optical micromanipulation of vital cells.
我们报道了由于多光子吸收现象，被限制在连续波（cw）近红外（NIR）多模光阱中的单细胞的细胞损伤情况。波长小于800 nm的近红外捕获光束能够通过双光子吸收过程损伤细胞。与单频真连续波近红外光阱相比，多模连续波光阱中的细胞损伤更为明显，这是由于纵向模式拍频导致的瞬态功率增强。用作捕获光束源的可调谐连续波钛宝石激光器中的部分模式锁定，在某些波长下会产生不稳定的亚纳秒脉冲，从而显著放大多光子吸收效应。我们建议使用单频长波长近红外捕获光束对活细胞进行光学微操作。
