Laser pulsetrain pulse-picker for subharmonic frequencies

我们请求支持为现有的研究激光系统购买配件，其中物理研究通常由NSERC发现基金资助，光子研究由CIPI的特殊应用基金资助，以及安大略省卓越中心的生物物理研究。3名教授和5名研究生的工作将得到这项资助的加强。现有的激光系统是完整的，功能齐全；该设备将允许我们在进行光学、材料加工或与先进和发展中的激光手术相关的生物组织相互作用的超快激光材料相互作用时，以激光脉冲传递的方式进入新的体制。我们最近在这个领域获得了一项专利，但进展一直受到资源限制，我们已经把一些领域让给了哈佛大学Mazur等团体。设备：一个脉冲拾取器选择系统，可以在两个不同的激光器之间有效地共享，这将使我们能够配置100MHz激光脉冲序列，以提供50 MHz， 25 MHz， 12 MHz或各种脉冲组合，以输送到不同的材料或生物组织。科学：飞秒激光器可以在短时间内将激光能量沉积到电子中，这比随后的晶格热化要短。在晶格能量完全耗散之前，高重复频率激光器（bbb1mhz）将下一个能量脉冲沉积到电子中，材料在热上松弛。通过在这两个时间尺度上控制能量的传递，我们相信我们可以在纳米尺度上对玻璃和其他光学材料的状态进行非平衡操纵。本质上，我们想要控制，在任何时候，材料中电子和声子之间的能量分配——大约，分别影响材料中的化学冲击和热/机械冲击。我们已经证明，这给我们提供了新的材料科学，以及微加工不同玻璃，陶瓷和其他脆性材料的新方法。

We request support to buy accessories for an existing research-laser system, for which physics research is generally funded by NSERC Discovery grant and photonics research by funding for special applications from CIPI, as well as biophysics research by Ontario Centres of Excellence.  Three professors and five graduate students work will be enhanced by this grant.   The existing laser-system is complete and functional;  this equipment will permit us to access new regimes in the way in which laser pulses are delivered when doing ultrafast laser-materials interaction for optics, materials-processing, or biotissue interaction relevant to advanced and developmental laser surgery.  We have a recent patent in this area, but progress has been resource-limited, and we have given up some ground to groups like that of Mazur at Harvard.   The Equipment:  a pulse-picker selection system, to be efficiently shared between two different lasers, that will let us configure our 100MHz laser pulsetrain to deliver instead 50 MHz, 25 MHz, 12 MHz, or various combinations of pulses for delivery to different materials or biotissues.   The Science:  Femtosecond lasers are known to deposit laser energy into electrons on a timescale short compared to the subsequent thermalization to the lattice.  High repetition-rate lasers (> 1 MHz) deposit the next pulse of energy to electrons before this lattice-energy has fully dissipated, and the material relaxed thermally.  By the paradigm of controlling fluence delivery across these two time-scale regimes, we believe we can make non-equilibrium manipulations of the state of glasses and other optical materials, and do this at a nanometer-scale.  Essentially, we want to control, at any time, the partition of energy between electrons and phonons in the material - approximately, to influence the chemical impact and the thermal/mechanical impact in the material separately.  We've shown this gives us access to new materials science, and new ways of microprocessing different glasses, ceramics and other brittle materials.