报告摘要：Single-cycle frequency combs enable study and control light-matter interaction at sub-cycle scale.They also lead to efficient mid-infrared comb generation. Besides, single- or sub-cycle pulses push the validity of envelope models to the limits,potentially unfolding new areas in nonlinear waveguide optics. Prior to our work, free-space components remain the major building blocks of single-cycle sources, hindering their applications and accessibility to the broader community. For example, direct nJ single-cycle pulse generation is crucial for exciting nanophotonic structures and cavities - a task that is challenging with the attenuation of higher-energy ultrashort pulses.We present the first implementation of a compact, turnkey and robust all-silica-fiber single-cycle source at 2 µm. The output pulses span from below 700 nm to 3500 nm at 6.8 fs duration, 100 MHz repetition rate, 215 kW peak and 374 mW average power. Through intra-pulse difference frequency generation, this fiber laser creates pulses from 6 to beyond 22 µm with stable carrier-envelope phase. Using electro-optic sampling, we record comb lines with 100 MHz separation. The configuration is general and can be extended to other wavelengths or repetition rate. Further improvements could provide sub-cycle all-fiber lasers.
个人简介：Dr. Sida Xing received his BEng (2013) and MEng (2015) from McGill University, Canada. He worked on mid-infrared fiber lasers since 2015 and received degree PhD degree from École Polytechnique Fédérale de Lausanne (EPFL), Switzerland in 2019. From 2019 to 2021, he worked in Scott Diddam’s group as a postdoctoral researcher in National Institute of Standards and Technology (NIST), USA. During this periods, he built the first all-fiber comb emitting single-optical-cycle pulses. He carries out experimental research in the fields of nonlinear fiber optics,fiber lasers/amplifiers and mid-infrared frequency comb spectroscopy.