Broadband spatiotemporal Gaussian Schell-model pulse trains

Abstract

A new class of partially coherent model sources is introduced on the basis of the second-order coherence theory of nonstationary optical fields. These model sources are spatially fully coherent at each frequency but can have broadband spectra and variable spectral coherence properties, which lead to reduced spatiotemporal coherence in the time domain. The source model is motivated by the spectral coherence properties of supercontinuum pulse trains generated in single-spatial-mode optical fibers. We demonstrate that such broadband light is highly (but not completely) spatially coherent, even though the spectral and temporal coherence properties may vary over a wide range. The model sources introduced here are convenient in assessing the spatiotemporal coherence of broadband pulses in optical systems.

The subtraction of mutually displaced Gaussian Schell-model beams

“…In classical optics, coherence theory [1][2][3] is a subject that continuously receives innovative contributions from countless authors, both within the scalar [4][5][6][7][8][9][10][11] and vectorial realm [12][13][14][15][16][17][18][19][20][21], including nonstationary states [22][23][24][25][26].…”

A phenomenological model of the X-ray pulse statistics of a high-repetition-rate X-ray free-electron laser

“…Similarly, since fluctuations in the pulse wavefront can no longer be considered stationary ergodic, measurements of the XFEL wavefront obtained by integrating over multiple pulses, such as in ptychography (Daurer et al, 2021), should be replaced in favour of single-shot methods (Sala et al, 2019). We suggest that these predictions of the model be explored further using frameworks for separating stationary and nonstationary components of the shot-to-shot pulse wavefield (Manea, 2009), and they may benefit from the large volume of literature on pulsed correlation functions that have been developed to describe the coherence function of laboratory light sources (Dutta et al, 2014(Dutta et al, , 2015.…”

Spatial-Temporal Self-Focusing of Partially Coherent Pulsed Beams in Dispersive Medium

“…In practice, many real sources, such as excimer lasers, free-electron lasers, or random lasers generate partially coherent pulse trains [43]. Usually, the Gaussian Schell-model (GSM) pulses with Gaussian correlation function are used to describe the partially coherent pulsed (PCP) field, which is called partially coherent GSM pulsed beams [44][45][46], whose propagation properties 2 of 13 are investigated in detailed [47][48][49][50][51][52][53][54][55]. In 2013, the non-uniformly PCP source with non-conventional correlation functions are introduced by Lajunen and Saastamoinen [56].…”