Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China.
J Biophotonics. 2019 Oct;12(10):e201900069. doi: 10.1002/jbio.201900069. Epub 2019 Jun 13.
Energetic femtosecond pulses at the 1700-nm window are a prerequisite for deep-tissue three-photon microscopy (3PM). Soliton self-frequency shift (SSFS) in photonic-crystal (PC) rod has been the only technique to generate such pulses suitable for 3PM. Here we demonstrate through SSFS in an air-core fiber, we can generate most energetic femtosecond soliton pulses at the 1700-nm window, 5.2 times higher than that from PC rod. However, the air-core soliton pulse width is 5.9 times longer than that of PC rod soliton. Based on comparative 3PM excited with both air-core and PC rod solitons, we propose the more suitable source for 3PM. We further elucidate the challenge of generating shorter soliton pulses from air-core fibers through numerical simulation.
在 1700nm 窗口处使用高能飞秒脉冲是实现深层三光子显微镜（3PM）的前提条件。在光子晶体（PC）光纤中自频移（SSFS）是产生适合 3PM 的飞秒脉冲的唯一技术。本文通过在空气芯光纤中实现 SSFS，在 1700nm 窗口处获得了比 PC 光纤高 5.2 倍的最高能量飞秒孤子脉冲，然而，空气芯孤子脉冲宽度是 PC 光纤孤子的 5.9 倍。基于对两种孤子源激发的 3PM 的对比，我们提出了更适合 3PM 的光源。我们进一步通过数值模拟阐明了通过空气芯光纤产生更短孤子脉冲的挑战。
