Ultrabroadband spectral transfer in extended focal zones: truncated few-cycle Bessel-Gauss beams

Young's Interference Experiment with Ultrashort-Pulsed Bessel Beams

“…We conclude that the pseudo-nondiffracting properties of TBB are well confirmed by Young-type interference experiments in close accordance to recently demonstrated ultrabroadband spectral and temporal transfer functions and near field propagation [5]. The particular properties of such beams are conserved over an extended, yet finite propagation distance if the truncation is performed in a self-apodizing setup.…”

“…At the distance that yielded maximum fringe contrast (z 0 = 9 mm from the axicons), a matrix of in total 7 laser-drilled holes was placed as hard apertures. The hole diameters were about 30 µm, matching the diameter of the first minimum of the Bessel distribution [5]. Diffraction patterns were detected by imaging planes at different distances onto a high-dynamicrange camera (Vosskuehler CCD-4000).…”

Needle beams: a review

“…The configuration is based on a field apodization and was referred to as 'selfapodizing truncation' [2]. As will be demonstrated in paragraph 4, selfapodizing truncation is also an effective way to generate needle pulses with undistorted spectrum and pulse duration [80,119,120].…”

“…Figure 6. Spatio-spectral propagation characteristics of an extended macroscale few-cycle needle beam generated with a reflective thin-film axicon and a diaphragm in self-apodizing configuration (Δλ = FWHM bandwidth, light source: 5-fs Ti:sapphire laser, central wavelength 800 nm, Rayleigh length > 20 cm[120]). xand z-scales differ by a factor of 10.…”