Horton Nicholas G, Xu Chris
School of Applied and Engineering Physics, Cornell University, 271 Clark Hall, Ithaca, New York, 14853, USA.
Biomed Opt Express. 2015 Mar 20;6(4):1392-7. doi: 10.1364/BOE.6.001392. eCollection 2015 Apr 1.
Signal generation in three-photon microscopy is proportional to the inverse-squared of the pulse width. Group velocity dispersion is anomalous for water as well as many glasses near the 1,700 nm excitation window, which makes dispersion compensation using glass prism pairs impractical. We show that the high normal dispersion of a silicon wafer can be conveniently used to compensate the dispersion of a 1,700 nm excitation three-photon microscope. We achieved over a factor of two reduction in pulse width at the sample, which corresponded to over a 4x increase in the generated three-photon signal. This signal increase was demonstrated during in vivo experiments near the surface of the mouse brain as well as 900 μm below the surface.
三光子显微镜中的信号产生与脉冲宽度的平方成反比。对于水以及1700nm激发窗口附近的许多玻璃，群速度色散是反常的，这使得使用玻璃棱镜对进行色散补偿不切实际。我们表明，硅片的高正色散可方便地用于补偿1700nm激发三光子显微镜的色散。我们在样品处实现了脉冲宽度降低两倍以上，这对应于产生的三光子信号增加超过4倍。在小鼠脑表面附近以及表面以下900μm处的体内实验中证明了这种信号增加。
