Next generation chirped volume Bragg gratings by means of fs laser inscription and investigation of their potential for new application ranges

通过飞秒激光刻字的下一代啁啾体布拉格光栅及其新应用范围潜力的研究

• 批准号: 448663633
• 负责人: Professor Dr. Stefan Nolte
• 金额: --
• 依托单位: Institut für Angewandte Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/448663633?language=en
• 关键词: Next; generation; chirped; volume; Bragg

Ultrashort pulse laser systems are key enablers for a variety of applications, e.g. in microscopy, spectroscopy, sensing or materials processing. For many of these applications, compact and reliable laser systems are essential. In recent years, chirped volume Bragg gratings (CVBG) have become available, replacing the traditionally used bulk gratings in the compressor of chirped-pulse-amplification systems and allowing for compact and rugged system designs. Typically, CVBG are based on photo-thermo-refractive glass, which limits the application to specific stretching parameters, power levels and wavelengths regimes. Exactly these limitations are addressed within this proposal to widen the applicability e.g. with respect to power or new spectral regions. As an example, the so-called fingerprint region in the mid-infrared wavelength range, which enables specific spectroscopic applications, is highly promising. However, currently available CVBG are not applicable here as their host material is not transparent at these wavelengths. Even more, the maximum achievable stretching/compression of laser pulses is limited by the maximum grating/host material length due to manufacturing reasons and the average power is limited due to intrinsic absorption.Ultrashort pulse laser inscription is a promising alternative for realizing VBG in other materials (glasses and crystals). While efficient reflective standard VBGs have already been demonstrated based on this approach for example in fused silica, CVBG are still to be developed at this high quality level. In addition, current ultrashort based VBG suffer from an inhomogeneity across their aperture limiting their application in high power laser systems.This is where the joint project between the Institute of Applied Physics at the Friedrich Schiller University in Jena (FSU) and the Institute of Applied Physics of the Russian Academy of Sciences (RAS) will make a unique contribution. The aim of the project is the development of a reliable inscription technique for high quality CVBG with an aperture up to 5mmx5mm. The main focus will be on fused silica as host material enabling for extremely robust - with respect to mechanical and optical power - and homogeneous grating structures. These devices will then iteratively be tested and compared to commercially available gratings within high power ultrashort pulse laser systems before finally extending the grating properties concerning stretching and bandwidth values not achievable with any available CVBG. Additionally, new host materials will be investigated and evaluated concerning their modifiability with ultrashort laser pulses to finally demonstrate CVBG within new glasses or crystals perfectly suited for specific applications dealing for example with extremely high average powers or new spectral ranges. Moreover, the technology developed within this project will create a large leverage for the ongoing optimization of ultrashort laser pulse systems.

超短脉冲激光系统是各种应用的关键推动因素，例如显微镜、光谱学、传感或材料加工。对于其中的许多应用，紧凑可靠的激光系统至关重要。近年来，啁啾体布拉格光栅（CVBG）已成为可用的，取代传统上使用的体光栅的压缩器的啁啾脉冲放大系统，并允许紧凑和坚固的系统设计。通常，CVBG基于光热折射玻璃，这将应用限制在特定的拉伸参数、功率水平和波长范围。正是这些限制在本提案中得到解决，以扩大适用性，例如关于功率或新的频谱区域。例如，中红外波长范围内的所谓指纹区域，它使特定的光谱应用成为可能，是非常有前途的。然而，目前可用的CVBG在这里不适用，因为它们的主体材料在这些波长下不透明。此外，由于制造原因，激光脉冲的最大拉伸/压缩受到光栅/基质材料最大长度的限制，并且由于固有吸收，平均功率受到限制。超短脉冲激光刻写是在其他材料（玻璃和晶体）中实现VBG的一种有前途的选择。虽然基于这种方法已经在熔融石英中证明了有效的反射标准VBG，但CVBG仍有待于在这种高质量水平上开发。此外，目前的超短VBG在其孔径上的不均匀性限制了其在高功率激光系统中的应用，这就是耶拿弗里德里希·席勒大学应用物理研究所（FSU）和俄罗斯科学院应用物理研究所（RAS）之间的联合项目将做出独特贡献的地方。该项目的目标是开发一种可靠的铭文技术，用于孔径高达5 mmx 5 mm的高质量CVBG。主要重点将是熔融石英作为基质材料，使非常强大的-相对于机械和光学功率-和均匀的光栅结构。然后，这些器件将反复进行测试，并与高功率超短脉冲激光系统内的市售光栅进行比较，然后最终扩展任何可用CVBG都无法实现的有关拉伸和带宽值的光栅特性。此外，还将研究和评估新的基质材料在超短激光脉冲下的可改性，以最终证明新玻璃或晶体中的CVBG非常适合处理极高平均功率或新光谱范围等特定应用。此外，该项目中开发的技术将为超短激光脉冲系统的持续优化创造巨大的杠杆作用。