Effects of primary spherical aberration, coma, astigmatism, and field curvature on the focusing of ultrashort pulses: Gaussian illumination and experiment

Abstract

We analyze the spatiotemporal intensity of Gaussian temporal envelope pulses with initial durations of 200 fs and a carrier wavelength of 810 nm at the paraxial focal plane of an achromatic doublet lens for a well-collimated incoming pulse beam by using the Seidel aberration theory for thin lenses with the stop at the lens. We analyze the effect of these aberrations in the focusing of ultrashort pulses for Gaussian illumination and present experimental results for 200 fs pulses focused by a near-IR achromatic doublet.

Strehl ratio for optical systems with ultrafast illumination

“…Generally, pulses are delivered to the sample through optical systems, where nonoptimized designs result in temporal broadening and poor spatial energy confinement. Effects of material dispersion and aberrations in pulsed source optical systems have been studied extensively using geometrical optics and Fourier analysis for optical components experiencing linear material interactions [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. However, none of the existing analytical approaches has demonstrated both fast and accurate results that can be integrated into analysis and optimization in optical design software.…”

Pulse front distortions caused by primary aberrations

“…3 shows the spatial intensity distribution in the presence of primary spherical aberration characterized by A 040 = −6 λ 0 for moments t = − 7000 T 0 , − 2394 T 0 , − 1800 T 0 and 500 T 0 calculated from Eqs. (13), (31) and (32). The pulse front predicted by the geometrical optics calculated from Eqs.…”

“…The effect of chromatic aberration on the temporal and spatial shape of an ultrashort pulse has already been studied extensively, both theoretically and experimentally [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. The influence of monochromatic aberrations on the pulse shape, that is the effect of spherical aberration [26][27][28][29], astigmatism, coma, curvature of field, and distortion [30,31] has also been investigated to a certain extent. Direct measurements of the spatio-temporal form of focused pulses distorted by aberrations have also been performed [32][33][34].…”

Temporal spreading generated by diffraction in the focusing of ultrashort light pulses with perfectly conducting spherical mirrors

“…Refractive systems produce temporal and spatial spreading of a limited bandwidth incident pulse at the focal plane, due to the GVD [2][3][4][5][6][7][8], the PTD [7,[9][10][11][12][13][14], and the aberrations [15][16][17][18][19][20][21]. GVD is generated in a pulse traveling inside the lens and it changes with the radial coordinate of the aperture of the lens.…”

“…PTD can be practically corrected in high numerical aperture microscope objectives by using apochromatic optics [7,14]. The aberrations also play a role in the spatiotemporal spreading of a pulse [18][19][20][21] but in microscope objectives these are highly corrected. There are other focused-pulse distortions such as an "X-shaped pulse" and the "forerunner pulse" that appear a certain distance from the focal plane [22][23][24][25][26][27]38].…”