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The introduction of ChatGPT has led to a significant increase in the utilization of Large Language Models (LLMs) for addressing downstream tasks. There's an increasing focus on cost-efficient training and deployment within this context. Low-cost training and deployment of LLMs represent the future development trend. This paper reviews the evolution of large language model training techniques and inference deployment technologies aligned with this emerging trend. The discussion on training includes various aspects, including data preprocessing, training architecture, pre-training tasks, parallel training, and relevant content related to model fine-tuning. On the inference side, the paper covers topics such as model compression, parallel computation, memory scheduling, and structural optimization. It also explores LLMs' utilization and provides insights into their future development., Comment: 30 pages,6 figures

Manipulation of intense pulse propagation in gas-filled capillaries is desirable for various high-field applications. Tuning the parameters of the driving laser pulse and the working gas is the conventional approach, and it provides limited capability of control. Here we demonstrate through numerical simulations a practical scheme to control the propagation of intense pulses. A weak ultraviolet pulse is launched into a capillary with a negative delay with respect to a main infrared pulse. The pulses begin to temporally overlap due to dispersion. As the main pulse self-compresses, the control pulse is strongly red-shifted due to cross-phase modulation. The frequency shifts of the two pulses mitigate pulse walk-off and allow an efficient coupling, substantially extending the effective interaction length. This interesting phenomenon may benefit applications such as high-order harmonic generation.

Ionization is one of the most fundamental processes in intense laser-matter interaction. It is extremely efficient for clusters in laser fields and often leads to surprisingly high charge states at moderate laser intensities. Here we reveal a novel ionization mechanism in laser-cluster interaction through particle-in-cell simulations. As the laser field ionizes a cluster, Brunel electrons pushed back into the clustered plasma form an attosecond bunches, impulsively exciting plasma oscillation. The resulting localized wake field further ionizes the cluster, causing a highly ionized rod-like core along the polarization axis. This anisotropic ionization is prominent using few-cycle pulses and may be washed out using longer pulses due to collisional ionization. This newly identified ionization channel can potentially provide complicated site-specific control of ionization in nanometer-scale targets.

Emphasizing the statistics of jumps crossing the strike and local time, we develop a decomposition of equity option risk premiums. Operationalizing this theoretical treatment, we equip the pricing kernel process with unspanned risks, embed (unspanned) jump risks, and allow equity return volatility to contain unspanned risks. Unspanned risks are consistent with negative risk premiums for jumps crossing the strike and local time and imply negative risk premiums for out-of-the-money call options and straddles. The empirical evidence from weekly and farther-dated index options is supportive of our theory of economically relevant unspanned risks and reveals ``dark matter" in option risk premiums.

Strong mid-infrared light-matter interaction has attracted extensive attention as it opens up new frontiers in nonlinear optics. Here we observe through simulations a novel aspect of mid-infrared pulse dynamics in a high-pressure gas-filled capillary, where a pulse with a power well below the critical power for Kerr self-focusing undergoes an astonishing rise of the peak intensity following an extremely efficient spectral broadening. This intensity enhancement is attributed to the Kerr-induced focusing of the supercontinuum. Our study provides an interesting perspective for controlling the laser intensity with possible applications in nonlinear light conversion driven by mid-infrared pulses., Comment: 5 pages, 6 figures

Submicron-sized targets are found in intense laser-cluster interaction experiments and laser-based material processing. Here we investigate the internal field localization due to Mie scattering and its effect on ionization dynamics in submicron-sized clusters using Mie calculation and particle-in-cell simulations. As a result of intertwined processes of pulse propagation and ionization, sub-micron nanofocusing dominates at lower intensity and gives rise to an ionization hotspot at the rear of the targets while plasma shielding wins over at a higher intensity, stopping further rear side ionization. As ionization is often the precursor of other processes, understanding the ionization dynamics of ultrafast laser pulses with wavelength-sized nanostructure can be relevant for intense laser-cluster experiments and femtosecond laser micro/nanomachining.

Ionization is a fundamental process in intense laser-matter interactions, and is known to cause plasma defocusing and intensity clamping. Here, we investigate theoretically the propagation dynamics of an intense laser pulse in a helium gas jet in the ionization saturation regime, and we find that the pulse undergoes self-focusing and self-compression through ionization-induced reshaping, resulting in a manyfold increase in the laser intensity. This unconventional behavior is associated with the spatiotemporal frequency variation mediated by ionization and spatiotempral coupling. Our results illustrate a new regime of pulse propagation and open up an optics-less approach for raising the laser intensity.

The processes of energy gain and redistribution in a dense gas subject to an intense ultrashort laser pulse are investigated theoretically for the case of high-pressure argon. The electrons released via strong-field ionization and driven by oscillating laser field collide with neutral neighbor atoms, thus effecting the energy gain in the emerging electron gas via a short-range inverse Bremsstrahlung interaction. These collisions also cause excitation and impact ionization of the atoms thus reducing the electron-gas energy. A kinetic model of these competing processes is developed which predicts the prevalence of excited atoms over ionized atoms by the end of the laser pulse. The creation of a significant number of excited atoms during the pulse in high-pressure gases is consistent with the delayed ionization dynamics in the pulse wake, recently discovered by Gao et al.[1] This energy redistribution mechanism offers an approach to manage effectively the excitation vs. ionization patterns in dense gases interacting with intense laser pulses and thus opens new avenues for diagnostics and control in these settings., Comment: 9 pages, 3 figures

We show theoretically and demonstrate experimentally that collapsing elliptically-polarized laser beams experience a nonlinear ellipse rotation that is highly sensitive to small fluctuations in the input power. For arbitrarily small fluctuations in the input power and after a sufficiently large propagation distance, the polarization angle becomes uniformly distributed in [0, 2$\pi$] from shot-to-shot. We term this novel phenomenon 'loss of polarization'. We perform experiments in fused-silica glass, nitrogen gas and water, and observe a significant increase in the fluctuations of the output polarization angle for elliptically-polarized femtosecond pulses as the power is increased beyond the critical power for self-focusing. We also show numerically and confirm experimentally that this effect is more prominent in the anomalous group-velocity dispersion (GVD) regime compared to the normal-GVD regime due to the extended lengths of the filaments for the former. Such effects could play an important role in intense-field light-matter interactions in which elliptically-polarized pulses are utilized., Comment: 6 pages, 4 figures