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This paper presents a single-shot technique for measuring CEP. The Temporal dispersion based One-shot Ultrafast Carrier envelope phase Analysis method (TOUCAN) is an arbitrary repetition rate single-shot CEP drift measurement technique based on dispersive Fourier transformations and has been experimentally tested at 100 kHz. TOUCAN was validated by a direct comparison of decimated data with an independent traditional CEP drift measurement technique. The impact of a temporal jitter on the CEP drift measurement is investigated and a new mitigation technique is shown to produce high accuracy jitter-free CEP drift extraction.

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High-harmonic generation (HHG) in crystals offers a simple, affordable and easily accessible route to carrier-envelope phase (CEP) measurements, which scales favorably towards longer wavelengths. We present measurements of HHG in ZnO using few-cycle pulses at 3.1µm. Thanks to the broad bandwidth of the driving laser pulses, spectral overlap between adjacent harmonic orders is achieved. The resulting spectral interference pattern provides access to the relative harmonic phase, and hence, the CEP.

We present single-shot electron velocity-map images of nanoplasmas generated from doped helium nanodroplets and neon clusters by intense near-infrared and mid-infrared laser pulses. We report a large variety of signal types, most crucially depending on the cluster size. The common feature is a two-component distribution for each single-cluster event: a bright inner part with nearly circular shape corresponding to electron energies up to a few eV, surrounded by an extended background of more energetic electrons. The total counts and energy of the electrons in the inner part are strongly correlated and follow a simple power-law dependence. Deviations from the circular shape of the inner electrons observed for neon clusters and large helium nanodroplets indicate non-spherical shapes of the neutral clusters. The dependence of the measured electron energies on the extraction voltage of the spectrometer indicates that the evolution of the nanoplasma is significantly affected by the presence of an external electric field. This conjecture is confirmed by molecular dynamics simulations, which reproduce the salient features of the experimental electron spectra.

Ablation and plasma mirror characteristics of Borofloat, BK7, and B270 glasses processed with 34 fs pulses of 800 nm central wavelength are compared in the 10 14-10 15 W/cm 2 intensity domain. With thresholds of 1.7-1.9 × 10 14 W/cm 2 , higher than those of fused silica, and depths saturating above 5×10 14 W/cm 2 , the three glasses behave similarly from the point of view of ablation. With reflectivity enhancements comparing favorably with that of fused silica, the glasses prove to be good plasma mirror hosts. With the steepest increase in time integrated transient reflectivity with intensity, Borofloat is the most promising candidate.

This paper presents a second harmonic assisted spectrally resolved interferometric technique that can overcome the limited spectral resolution of commercially available spectrometers in the mid-infrared. The discussed scheme was validated by measuring the group delay of several well-known and frequently used materials. Our main motivation was to characterize the spectral phase shift of newly designed and manufactured dispersive mirrors to be used for mid-infrared (MIR) post-compression. These mirrors were successfully implemented in the post-compression stage of our MIR laser system, where pulse duration was shortened below two optical cycles and the pulse peak power increased by 30.3% compared to the original output.

Broadband terahertz radiation can be efficiently produced by mixing laser pulses of different colors in the mid-infrared (MIR) and longwave-infrared (LWIR) spectral region. In this paper, we report on a numerical investigation of ultrashort terahertz pulse generation from plasmas created in nitrogen gas by two-color laser pulses with the fundamental laser pulse wavelength between 2.15 and 15.15 µm, in order to explore the efficiency of the terahertz pulse generation process. The results show that the electron acceleration efficiency increases monotonically with the fundamental laser pulse wavelength. The most intense terahertz pulse generation is observed at 12.30 µm with four optical-cycle laser pulses with 2.5 GW peak power. The results show that the terahertz pulse generation with a MIR laser is one order of magnitude and with a LWIR laser is two orders of magnitude more efficient than the terahertz pulse generation with Ti:Sapphire lasers using the exact same pulse parameters. The terahertz pulse generation efficiency is also known to be very sensitive to the relative phase between the components of the two-color laser pulses. One of the most useful tools to control the relative phase and optimize the terahertz pulse intensity is thin dielectric plates. It has been shown that alkaline halides and alkaline earth halides have suitable optical properties for the relative phase control for efficient terahertz pulse generation in the MIR spectral range.