We present a systematic study on linear propagation of ultrashort laser pulses in media with dispersion, dispersionless media and vacuum. The applied method of amplitude envelopes gives the opportunity to estimate the limits of slowly warring amplitude approximation and to describe an amplitude integro-differential equation, governing the propagation of optical pulses in single cycle regime. The well known slowly varying amplitude equation and the amplitude equation for vacuum are written in dimensionless form. Three parameters are obtained defining different linear regimes of the optical pulses evolution. In contrast to previous studies we demonstrate that in femtosecond region the nonparaxial terms are not small and can dominate over transverse Laplacian. The normalized amplitude nonparaxial equations are solved using the method of Fourier transforms. Fundamental solutions with spectral kernels different from Fresnel one are found. One unexpected new result is the relative stability of light pulses with spherical and spheroidal spatial form, when we compare their transverse enlargement with the paraxial diffraction of lights beam in air. It is important to emphasize here the case of light disks, i.e. pulses whose longitudinal size is small with respect to the transverse one, which in some partial cases are practically diffractionless over distances of thousand kilometers. A new formula which calculates the diffraction length of optical pulses is suggested.
Interleaved diffractive networks for information transfer through random diffusers
University of California, Los Angeles（加州大学洛杉矶分校）；California NanoSystems Institute (CNSI), University of California, Los Angeles（加州纳米系统研究所）；Electrical and Computer Engineering Department, University of California, Los Angeles（加州大学洛杉矶分校电气与计算机工程系）；Bioengineering Department, University of California, Los Angeles（加州大学洛杉矶分校生物工程系）
Generating non-diffracting bottle beams with a flat multi-level diffractive lens
Quantlight and High Harmonics Lab Pvt. Ltd.（量子光与高次谐波实验室私人有限公司）；Graduate School of Engineering, Chiba University（千叶大学研究生院）；Molecular Chirality Research Centre, Chiba University（千叶大学分子手性研究中心）；Laboratory of Nonlinear Optics, Institute of Astronomy, University of Latvia（拉脱维亚大学天文学研究所非线性光学实验室）；Laser Centre, Institute of Physical Chemistry, Polish Academy of Sciences（波兰科学院物理化学研究所激光中心）；Department of Physics, Indian Institute of Technology Ropar（印度理工学院罗帕尔分校物理系）；Department of Electrical and Computer Engineering, University of Utah（犹他大学电气与计算机工程系）；Oblate Optics, Inc.（扁球光学有限公司）；Department of Electrophysics, National Yang Ming Chiao Tung University（国立阳明交通大学电光子学系）
Low peak-power pulse compression in gas-filled Herriott cells in the 2 μm wavelength range
Helmut Schmidt University（赫尔穆特·施密特大学）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；n2-Photonics GmbH（n2光子有限公司）；Leibniz University Hannover（汉诺威莱布尼茨大学）
