Hou D X, Butler D L, He L M, Zheng H Y
Precision Engineering and Nanotechnology Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
Lasers Med Sci. 2009 Mar;24(2):151-4. doi: 10.1007/s10103-008-0540-8. Epub 2008 Jan 29.
The feasibility of low energy processing in ocular tissues with femtosecond laser sources was investigated in this research. One laser source was a femtosecond amplifier, and the other was a femtosecond oscillator. The amplifier used in this experiment was a CPA-2001 (Clark-MXR, Inc), with 150 fs pulse duration and 1 kHz repetition rate. The femtosecond oscillator (model 900-B Mira) produced a 200 fs pulse duration and a 76 MHz repetition rate. Both these two laser systems operated at 800 nm wavelengths. Firstly, the pulse intensity thresholds in water produced by the two laser sources were compared. The optical breakdown probability analysis shows that the pulse energy threshold achieved by the oscillator was less than 10% of that achieved by the amplifier. Then, the non-linear propagation of the femtosecond pulses in the ocular tissues was studied with the femtosecond oscillator. The results showed a potential for pulse energy processing at the nanojoule level with a femtosecond oscillator in glaucoma treatment.
本研究探讨了使用飞秒激光源对眼组织进行低能量处理的可行性。一种激光源是飞秒放大器，另一种是飞秒振荡器。本实验中使用的放大器是CPA - 2001（克拉克 - MXR公司），脉冲持续时间为150飞秒，重复频率为1千赫兹。飞秒振荡器（型号900 - B Mira）产生的脉冲持续时间为200飞秒，重复频率为76兆赫兹。这两种激光系统均工作在800纳米波长。首先，比较了两种激光源在水中产生的脉冲强度阈值。光学击穿概率分析表明，振荡器达到的脉冲能量阈值小于放大器达到的脉冲能量阈值的10%。然后，使用飞秒振荡器研究了飞秒脉冲在眼组织中的非线性传播。结果表明，在青光眼治疗中，飞秒振荡器在纳焦耳水平进行脉冲能量处理具有潜力。
