In-line holographic imaging and electron density extraction of ultrafast ionized air filaments

Virtual hyperbolic metamaterials for manipulating radar signals in air

“…The dynamics of the electron density (N e ), the density of positive (N þ ) and negative ions (N À ) inside each filament can be calculated using rate equations 16,17 …”

Application of inverse Abel techniques in in-line holographic microscopy

“…In the field of holographic microscopy [1][2][3][4][5][6], the treatment of inverse problems, as for instance, that of recovering the volume of the three-dimensional distribution of the refractive index, is based on the application of various techniques of Abel transform. The Abel transform [7][8][9] is actually a solution of the inverse mathematical problem of retrieving the three-dimensional distribution of a physical property such as the refractive index or absorption on the basis of the knowledge of a single projection.…”

“…This approach is widely applied in tomographic imaging applications where the object under study is somewhat static. On the other hand, it is quite difficult to retrieve the large number of projections required in the case of dynamical objects encountered in ultrafast pump-probe experiments [1][2][3][4][5][6]. In this case the objects under study are laser induced perturbations in the refractive index of a transparent medium with micron sized spatial dimensions.…”

“…At this point, it should be noted, that BASEX method is up to now mainly applied, with great success, to two-dimensional projections of three-dimensional spherical objects encountered in photoelectron imaging spectroscopy . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 In this work we compare the BASEX and the F-H methods by using them to retrieve the distribution of three-dimensional objects with cylindrical symmetry from two-dimensional projections that are commonly encountered in pump-probe experiments [2][3][4][5][6]. In particular we numerically study the effect of noise on the reconstruction results for various typical distributions.…”

Dynamics of strong-field laser-induced microplasma formation in noble gases

“…A considerable amount of research has focused on determining the electron concentration in fs laser-induced plasmas including interferometry [13,14], longitudinal diffractometry [15], in-line holographic imaging [16][17][18] electric conductivity [19,20] and shadowgraphic techniques. Shadowgraphic measurements are performed either by measuring the absorption of a probe laser as a consequence of inverse Bremsstrahlung [21] or the change in the refractive index gradient on a probe [22].…”