Monolithic, mode-locked Titanium-Sapphire lasers with repetition rates in the range of 30 GHz to 300 GHz

单片锁模钛蓝宝石激光器，重复频率范围为 30 GHz 至 300 GHz

• 批准号: 408250400
• 负责人: Professor Dr. Ulrich Wittrock
• 金额: --
• 依托单位: Fachbereich Physikingenieurwesen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408250400?language=en
• 关键词: Monolithic; mode; locked; Titanium; Sapphire

The goal of this project is to investigate a new type of mode-locked Titanium-doped Sapphire (“Ti:Sa”) laser. This will be the first monolithic Ti:Sa laser and the first mode-locked solid state laser to have a repetition rate in the range of 30 GHz up to 300 GHz. The unusual large gain bandwidth of Ti:Sa supports a large number of longitudinal modes despite the resonators having to be short. This leads to background-free ultra-short pulses at unprecedented repetition rates. For example, a Ti:Sa laser with 1 THz repetition rate could still have more than 100 modes. The laser is a simple, thin Ti:Sa disk with a thickness between 0.3 mm and 3 mm that bears dispersion-compensating coatings on both sides. Calculations presented in the proposal show that it is possible to achieve Kerr-Lens mode-locking in such a simple structure. We want to investigate the mode-locking conditions and the noise properties of this new type of Ti:Sa laser.The proposed monolithic setup has important advantages for laser operation. There are no antireflective coatings inside the resonator. This prevents etalon effects and reduces losses. The short Ti:Sa crystals allows dispersion compensation using just the coatings on the two surfaces of the crystal, making quasi-soliton mode-locking possible. The pulse repetition rate will be very constant, i. e. pulse timing jitter will be low, because there can be no vibration of resonator mirrors or air turbulence inside the resonator. This inherent stability of monolithic laser systems is known from monolithic single frequency lasers. A mode-locked laser with stable fs-pulses at tens of GHz or hundreds of GHz repetition rate will have applications for dual-comb spectroscopy, astro-combs, ultrafast pulse shaping, optical communication, or frequency metrology. The high repetition rate allows separating the modes with a dispersive system of moderate resolution. This leads to compact and cost-effective systems for frequency comb applications. Despite the high repetition rate, the peak power of such a laser will still be several tens or thousands times higher than its average power, meaning that hundreds of Watts or even a Kilowatt can be expected. This will set this Ti:Sa laser apart from mode-locked semiconductor lasers which have reached 100 GHz repetition rate albeit with a peak power of less than 2 W. A high peak power means that nonlinear optical processes can be driven which is beneficial for pulse characterization and for applications.With future advances in output power and beam quality of blue and green diode lasers it should be possible to pump our Ti:Sa laser directly with a diode laser. This would yield a very compact and rugged femtosecond laser and frequency comb.

该项目的目标是研究一种新型锁模钛掺杂蓝宝石（“Ti:Sa”）激光器，这将是第一个单片 Ti:Sa 激光器和第一个具有锁模固态激光器。尽管谐振器必须很短，但 Ti:Sa 的重复频率范围为 30 GHz 至 300 GHz，其异常大的增益带宽可支持大量纵模。例如，具有 1 THz 重复率的 Ti:Sa 激光器仍然可以具有 100 多个模式。该激光器是一个简单、薄的 Ti:Sa 盘，厚度在 0.3 毫米到 3 毫米之间，具有色散补偿。提案中提出的计算表明，在如此简单的结构中实现克尔透镜锁模是可能的，我们希望研究这种新型的锁模条件和噪声特性。 Ti:Sa 激光器。所提出的整体装置对于激光操作具有重要优势，谐振器内部没有抗反射涂层，这可以防止标准具效应并减少损耗。短的 Ti:Sa 晶体允许仅使用两个表面上的涂层进行色散补偿。晶体的，使得准孤子锁模成为可能，即脉冲定时抖动将很低，因为谐振器镜或空气不会振动。单片单频激光器具有数十 GHz 或数百 GHz 重复率的稳定 fs 脉冲，因此单片激光系统的这种固有稳定性将应用于双梳光谱、天文。 -梳、超快脉冲整形、光通信或频率计量高重复率允许使用中等分辨率的色散系统来分离模式，这使得频率梳系统变得紧凑且经济高效。尽管重复率很高，但这种激光器的峰值功率仍然比其平均功率高出几十或几千倍，这意味着可以预期数百瓦甚至千瓦，这将设置这种Ti:Sa激光器。除了已达到 100 GHz 重复频率但峰值功率小于 2 W 的锁模半导体激光器之外。高峰值功率意味着可以驱动非线性光学过程，这有利于脉冲表征和应用。随着未来的进步输出功率和光束质量蓝色和绿色二极管激光器应该可以直接用二极管激光器泵浦我们的 Ti:Sa 激光器，这将产生非常紧凑且坚固的飞秒激光器和频率梳。