Figure 1

(a) Measured alignment of 1 atm of ${\mathrm{N}}_2$ and ${\mathrm{O}}_2$ at room temperature (295 K) by a 110 fs, 800 nm, $4.1\times {10}^{13}\mathrm{W}/{\mathrm{cm}}^2$ laser pulse. The effective alignment of air is synthesized from the ${\mathrm{N}}_2$ and ${\mathrm{O}}_2$ plots (see text). (b) Setup showing the DPI. $\mathrm{QWP}=\mathrm{\text{quarter}}$ wave plate; $\mathrm{HWP}=\mathrm{\text{half}}$ wave plate; $\mathrm{TFP}=\mathrm{\text{thin}}$ film polarizer. The right panel shows beam images of filamentation and white light generation for increasing pulse power up to $\sim 2.8P_{\mathrm{cr}}$.Reuse & Permissions

Figure 2

1D integrated images of probe filament as a function of delay (30 fs steps) through the pump-probe temporal overlap ($t=0$). The laser pulse width is 130 fs. Pump/probe energies are $1.4\mathrm{mJ}/2\mathrm{mJ}$ ($1.1P_{\mathrm{cr}}/1.6P_{\mathrm{cr}}$). Each image slice is a 30-shot average. Selected 2D images are shown as insets, as is a beam center lineout of the air alignment response and the pump pulse (red squares) in the $t=0$ region. Note that $n_2$ obtained from the inset gives $P_{\mathrm{cr}}=10\mathrm{GW}$ at the laser pulse peak and $P_{\mathrm{cr}}=4.3\mathrm{GW}$ at the molecular response peak.Reuse & Permissions

Figure 3

(a) 1D integrated images of probe filament as a function of delay (30 fs steps) through the air revival near $t=8\mathrm{ps}$, comprised of the ${\mathrm{N}}_2$ full revival $t\sim T_{\mathrm{N}2}\sim 8.3\mathrm{ps}$) and the ${\mathrm{O}}_2$ three-quarter revival ($t=3/4T_{\mathrm{O}2}\sim 8.7\mathrm{ps}$). Pump/probe energies are $1.4\mathrm{mJ}/2.5\mathrm{mJ}$ $1.1P_{\mathrm{cr}}/2P_{\mathrm{cr}}$). Selected 2D images are shown as insets, as is a lineout of the air alignment response in the $t=8\mathrm{ps}$ region. (b) Pump pulse energy scan ($0.7P_{\mathrm{cr}}$ through $2.5P_{\mathrm{cr}}$), holding probe energy constant at 4.35 mJ ($3.4P_{\mathrm{cr}}$). The bottom panel has pump/probe energies $4.65\mathrm{mJ}/3.05\mathrm{mJ}$ ($3.6P_{\mathrm{cr}}/2.4P_{\mathrm{cr}}$).Reuse & Permissions

Figure 4

(a) Pump ($2.3P_{\mathrm{cr}}$) and probe ($2.5P_{\mathrm{cr}}$) filament central spots in far field with initial $\sim 0.1\mathrm{mrad}$ misalignment, where (i) the probe delay is detuned from revivals, (ii) the probe is delayed to location $C$ in Fig. 3a, and (iii) the probe is delayed to location $A$ in Fig. 3a. (b) Probe filament spectrum as a function of delay (30 fs steps) through the air alignment revival near $t=8\mathrm{ps}$.Reuse & Permissions