High Energy Sub-100 Femtosecond Fiber Lasers at 2 Micron

There is an urgent need to develop a new high-energy 2m ultrafast fiber laser system in order to achieve the optimized efficiency of the ESASE process, which is beneficial in areas ranging from atomic and molecular sciences to chemical, materials, and biological studies. To reach the mid-IR wavelengths for ESASE application, the traditional way is to shift the wavelengths of these commercially available ultrafast pulse laser systems to the wavelengths of 2m or longer with substantial cost-ineffective efforts. It is of great interest to generate high energy femtosecond pulses at 2m directly from thulium (Tm) - doped fiber lasers and amplifiers. AdValue Photonics proposes a high-energy 2m femtosecond fiber CPA laser system that could deliver 5mJ pulses with pulse duration of & lt;100 fs at the repetition rate of 10 kHz for ESASE application, which start from an environmentally stable mode-locked Tm-doped all-fiber oscillator. An extra large-mode-area heavily-Tm-doped solid-core silicate Bragg fiber with 100-m core diameter will be used as the main amplifier which boosts the pulse energy to mJ level and maintains effective single-mode operation. We successfully demonstrated 2m mode-locked fiber laser with spectral width of greater than 50nm, which can be compressed to & lt;100fs and amplified pulse energy to larger than 5J. We successfully fabricated a Bragg fiber, which guides at 2m. Both experimental and simulation results show that the objectives of this proposal is realistic and achievable. We shall develop deliverable prototype 2m mode-locked fiber laser that delivers 5mJ pulses with pulse duration of & lt;100fs at the repetition rate of 10 kHz. Commercial Applications and Other Benefits: Our proposed technology will boost 2m fiber lasers to a new high-energy level. This high energy ultrafast infrared light source will benefit many processes and phenomena in high intensity physics, such as photo-fragmentation and Coulomb explosion in atomic clusters. This innovative technology will open up a lot of new opportunities for commercial applications. Some commercial applications are frequency metrology, material processing, micromachining, waveguide writing, medical treatments, laser microscopy and tomography, and characterization of high-speed electronics.