Development of UV excitation CARS microscopy system and applications to biological tissue measurement

我们利用两台同步的PS-Ti：蓝宝石激光器研制了一套多焦点CARS显微系统。CARS显微镜需要两个波长不同的激光器，峰值强度高，光谱带宽在几厘米左右，大波长扫描范围在2000厘米左右。为此，我们研制了一套以两台同步的PS-Ti：蓝宝石激光器为光源的系统。采用微透镜阵列激发和观察平行点，缩短了测量时间。对于在近红外和紫外光下没有吸收的聚苯乙烯微珠，由于紫外光强度低，只能通过近红外激发获得CARS光谱和图像。而对于吸收波长在400 nm左右的人红细胞，由于电共振的增强作用，在紫外光激发下获得了清晰的CARS光谱和图像，从而证实了电共振增强对CARS显微镜的重要作用。

We developed a multi-focus CARS microscopy system using two synchronized ps-Ti : Sapphire lasers. CARS microscope require two lasers with different wavelength, high peek intensity, narrow spectral bandwidth around a few cm^<-1>, and large wavelength scanning range about 2000cm^<-1>. Therefore, we developed a system using two synchronized ps-Ti : Sapphire lasers for light source. A micro-lens array is used to excite and observe parallel points for shortening the measurement time. The second harmonics of lasers are also available to use for electric resonance enhancement.For the polystyrene beads without absorption at near-IR and UV, the CARS spectrum and image are obtained by near-IR excitation only, because of low intensities of UV beam. On the other hand for human erythrocyte which has absorption around 400 nm, Clear CARS spectrum and image are obtained by UV excitation, because of electric resonance enhancement.As the results, it was confirmed that the electric resonance enhancement is the important for CARS microscopy.