Fiber laser-driven gas plasma-based generation of THz radiation with 50-mW average power

Abstract

We present on THz generation in the two-color gas plasma scheme driven by a high-power, ultrafast fiber laser system. The applied scheme is a promising approach for scaling the THz average power but it has been limited so far by the driving lasers to repetition rates up to 1 kHz. Here, we demonstrate recent results of THz generation operating at a two orders of magnitude higher repetition rate. This results in a unprecedented THz average power of 50 mW. The development of compact, table-top THz sources with high repetition rate and high field strength is crucial for studying nonlinear responses of materials, particle acceleration or faster data acquisition in imaging and spectroscopy.

Gas-plasma-based generation of broadband terahertz radiation with 640 mW average power

“…The efficiency of the generation process at this wavelength is still comparable to that achieved in GaP and LiNbO 3 [21][22][23]. In a previous publication [6] we demonstrated the generation of 50 mW average power with an efficiency of 4 • 10 −4 .…”

“…One very promising concept is the frequency conversion of high-power, ultra-short laser pulses in the near-and mid-infrared spectral region. Here, the most powerful sources so far have reached 50 mW [6], 66 mW [7] and 144 mW [8]. For the further scaling of the generated THz radiation, either the efficiency or the driving laser power has to be increased.…”

1 kW, 10 mJ, 120 fs coherently combined fiber CPA laser system

“…https://doi.org/10.1364/OL.417032 Ultrafast lasers are highly demanded tools, allowing generation of high-harmonics [1] or terahertz radiation [2] and opening up new and most challenging fields such as laser particle acceleration [3]. Besides necessarily requiring ultrashort pulse durations and high pulse energies at a diffraction limited beam quality, such applications typically strongly benefit from high average powers, improving processing or measurement speeds and signal-to-noise ratios.…”

Single-cycle, MHz repetition rate THz source with 66 mW of average power

“…In spite of the potential of these, as well as other high-average power amplifier systems, only few attempts have been made so far to drive THz generation with the available state-of-the-art high driving average powers, most likely because of the large difficulties related to heat handling and damage in most commonly used media for frequency down-conversion.Very recently, THz generation in two-color plasma filaments was explored in combination with high-average power excitation because of its intrinsically damage-free operation and pump pulse duration limited THz bandwidths, with conversion efficiencies in the 10 -4 range. In this experiment, a 120 W Yb-fiber amplifier system was used to generate 50 mW at a repetition rate of 100 kHz [11], which represents the highest THz average power demonstrated so far. However, in this result the THz waveform and spectrum have not been fully characterized yet, limiting the application possibilities of this system.…”

“…Very recently, THz generation in two-color plasma filaments was explored in combination with high-average power excitation because of its intrinsically damage-free operation and pump pulse duration limited THz bandwidths, with conversion efficiencies in the 10 -4 range. In this experiment, a 120 W Yb-fiber amplifier system was used to generate 50 mW at a repetition rate of 100 kHz [11], which represents the highest THz average power demonstrated so far. However, in this result the THz waveform and spectrum have not been fully characterized yet, limiting the application possibilities of this system.…”