Filamentation of ultra-short TW-class lasers recently opened new perspectives in
atmospheric research. Laser filaments are self-sustained light structures of 0.1–1 mm in …

We carry out a combined theoretical and experimental investigation on the population
distributions in the ground and excited states of tunnel-ionized nitrogen molecules at various …

It has been known for many years that during filamentation of femtosecond light pulses in air,
gain is observed on the B to X transition in N 2+. While the gain mechanism remains …

摘要高强度的飞秒激光在非线性介质成丝过程中会产生一系列非线性效应, 如强场电离,
转动拉曼, 高次谐波, 激射等, 这些非线性效应与强场下分子的复杂运动有关 …

The temporal evolution of a plasma channel at the trail of a self-guided femtosecond laser
pulse was studied experimentally and theoretically in air, nitrogen (with an admixture of∼ …

The word laser usually refers to a complex instrument made of various optical elements,
including an active medium, an optical resonator, and a power supply. In most applications …

We investigate the dynamics of cavity-free lasing from neutral nitrogen molecules in
femtosecond laser filaments. An important difference of intensity and temporal duration is …

We develop a background-free single-beam coherent Raman scattering technique enabling
the high-sensitivity detection of greenhouse gases. In this scheme, Raman coherence …

Amplified Spontaneous Emission is ubiquitous in systems with optical gain and is
responsible for many opportunities and shortcomings. Its role in the progression from the …

A column of bright filament is generated when a strong 800 nm femtosecond laser
propagates in pure nitrogen gas, from which some fluorescence emission lines are …