Spectrum Compression of Gaussian Pulse from Annular Aperture in Far-Field

Abstract

The far-field spectral characteristics of a time-dependent Gaussian pulse diffracted by a circular aperture with a central obstruction (annular-aperture) are studied both theoretically and numerically. It was shown that the central obstruction causes diffracted spectrum compression, which can be compared with the normal circular aperture (without a central obstruction) without this effect. Also, the diffracted spectral intensity distributions with red and blue shifts of the maximum are presented.

Diffraction of ultrashort Gaussian pulses within the framework of boundary diffraction wave theory

“…Spatio-temporal couplings of ultrashort pulses have come to play ever increasing-both desirable and undesirable-roles in important applications, including pulse compression, shaping, imaging, and focusing (see e.g. [1][2][3] and references therein). The propagation of an ultrashort pulse exposes it to many such distortions, of which some remain rather surprising.…”

Spectral Switches of Gaussian Pulse from Adjustable Tilted Mirror in Far Field

“…Many different kinds of behavior can exist around singular points, e.g., wave front dislocations, optical vortices, 3) spectral switches, and spectra distortions. [4][5][6][7][8][9][10][11][12] Most earlier publications used monochromatic waves as light sources [1][2][3] to discuss this singular behavior. In more recent studies, it has been found that, for polychromatic light 4,8) or broad-band short pulse wave fields 5,6) drastic spectral changes can also be exhibited.…”

“…[4][5][6][7][8][9][10][11][12] Most earlier publications used monochromatic waves as light sources [1][2][3] to discuss this singular behavior. In more recent studies, it has been found that, for polychromatic light 4,8) or broad-band short pulse wave fields 5,6) drastic spectral changes can also be exhibited. These spectral changes are then analyzed and shown to be related to the spatial correlation of the light sources 12) (correlation-induced spectral changes) and/or with the limiting aperture [4][5][6][7][8] (aperture-induced spectral changes).…”

“…In more recent studies, it has been found that, for polychromatic light 4,8) or broad-band short pulse wave fields 5,6) drastic spectral changes can also be exhibited. These spectral changes are then analyzed and shown to be related to the spatial correlation of the light sources 12) (correlation-induced spectral changes) and/or with the limiting aperture [4][5][6][7][8] (aperture-induced spectral changes). The latter is also referred to as ''aperture dispersion''.…”

“…The latter is also referred to as ''aperture dispersion''. 5,6,13,14) Since then, Many studies have used different kinds of light sources (e.g., Bessel-Gauss beam, 11) Gaussian-Schell model, 9) Gaussian pulse 5,6) ) or various optical elements (e.g., single slit, 10) double slit, 8) circular aperture, 13) gratings 14) ) to study these spectral anomalies in the near field or far field; some of these studies have been experimentally verified. [15][16][17] In this article, an adjustable tilted mirror is used to cause the far field spectral changes for a Gaussian short pulse.…”