Beam shaping of ultrashort laser pulses by means of acousto-optic deflection and refraction

具有几MHz重复率和超过50 W平均功率的超短脉冲激光器是商业上可获得的。理论上，这种激光器确实允许以增加的烧蚀速率进行微结构化。然而，在目前的实践中，光束引导和整形技术引起严重的限制。本项目的主要目标是利用声光偏转和折射技术、实验分析和理论进展，为新一代超短激光脉冲的新型光束引导和整形方法奠定基础。特别是，我们寻求显着减少并发光束引导和光束整形系统所造成的微结构的限制，我们的初步研究表明，快速和圆柱透镜自由光束引导和基本光束整形是可能的，通过同步的声光偏转器的控制信号与超短激光脉冲的发射。我们的研究结果强烈表明，该项目的主要目标可以通过开发控制信号来实现，这些控制信号允许使用衍射操作模式进行光束引导、光束整形和光束分裂。利用这种方法，光束的部分可以独立于同一光束的其他部分被引导和成形，而光束形状和光束分裂从一个激光脉冲到下一个激光脉冲是可变的。此外，我们打算开发的控制信号，可以用来让声光偏转器操作折射，而不是衍射。然后，由于衍射的衍射功率损失可以防止。为了实现本研究建议的目的，需要开发分析模型和实验装置的规划，实现和表征。为了证明新方法的有效性，我们还打算在微观结构中进行实验。原型实现和应用被预见到识别和解决将新技术转移到应用的实际挑战。通过实践论证，使创新的高度具体化、明显化、醒目化。在微结构化中，可以使用更少的脉冲和更高的重复率来产生几何结构，从而实现远高于当今可能的那些的期望的烧蚀率。

Ultrashort pulsed lasers with repetition rates of several MHz and an average power of more than 50 W are commercially available. In theory such lasers do allow for microstructuring at increased ablation rates. However in current practice, the beam guiding and shaping technology provoke severe limitations. Concurrent machinery, for example, does not allow the user to efficiently use the available pulse energy or repetition rate in the micro production technology.Primary objective of the project is to found the basis of a new generation of novel beam guiding and shaping methods of ultrashort laser pulses by the use of acoustooptical deflection and refraction technologies, experimental analysis and theoretical advances. Particularily, we seek to significantly reduce limitations in microstructuring caused by concurrent beam guiding and beam shaping systems.Our preliminary research shows, that fast and cylinder lens free beam guiding and basic beam shaping is possible by synchronizing the control signal of the acoustooptical deflector with the emission of the ultrashort laser pulse. Our findings strongly indicate, that the primary objective of the project can be achieved by developing control signals, which allow for beam guiding, beam shaping and beam splitting using diffractive mode of operation. With such methods fractions of a beam can be guided and shaped independently from other fractions of the same beam while beam shape and beam splitting are alterable from one laser pulse to the next one. Furthermore we intend to develop control signals that can be used to allow acoustooptic deflectors to operate by refraction instead of diffraction. Then, diffractive power losses due to diffraction can be prevented.To achieve the aim of this research proposal analytical models need to be developed and an experimental setup has to be planned, realized and characterized. To demonstrate the effectiveness of the new methods we also intend to carry out experiments in microstructuring. Prototypical implementation and application is forseen to identify and solve practical challenges of transferring the novel technology to the application. By practical demonstration we intend to make the high degree of innovation concrete, obvious and striking. In microstructuring, geometric structures may be produced using less pulses and higher repetition rates enforcing desirable ablation rates that are far higher than those possible today.