Spatial properties of a diffracted high-order radial Laguerre–Gauss LG_p0beam

Abstract

Diffraction of a high-order radial Laguerre-Gauss LG p0 beam truncated by a circular aperture is considered. In contrast with the truncated usual Gaussian LG 00 beam, which is not Gaussian in the near-field and quasi-Gaussian in the far-field, the truncated LG p0 beam (for p = 1 to 4) behaves very differently. Depending on the diaphragm size, the radial intensity distribution of a truncated LG p0 beam in the far-field (focal plane of a lens) can take the shape of (i) a flat-top, (ii) a hollow beam and (iii) one central peak and a ring having the same intensity. In addition, clipping-even weakly-of an LG p0 beam splits the usual focal point into two.

Reduced volume and reflection for bright optical tweezers with radial Laguerre–Gauss beams

“…3 . From various metrics, here we choose to quantify localization by way of trap vibrational frequencies near the bottom of the trapping potential (i.e., the central intensity maximum for a red-detuned trap), which are modified by pupil apodization and diffraction effects for focused radial LG beams according to their radial mode number ( 37 ).…”

“…Further increase of the filling factor will misrepresent the LG beam on the input pupil, and as a result, the foundation of spatial reduction due to Gouy phase superposition will have to be reconsidered. The pupil apodization effects will modify the spatial properties of the focused radial LG beams according to their radial mode number ( 37 ). In fact, larger filling factor truncates the LG beams and can generate completely different field profiles (even bottle beams for a single LG mode input).…”

Reduced volume and reflection for bright optical tweezers with radial Laguerre-Gauss beams

“…The full widths at half maxima for the intensity distributions along x, y, z in Figure 1 of the main text are ∆x 0 = ∆y 0 = 1.17 µm and ∆z 0 = 6.28 µm for E 0 , and ∆x Σ = ∆y Σ = 0.51 µm and ∆z Σ = 1.5 µm for E Σ . Appendix A: Filling factor dependence, trap frequencies and dimensions apodization and diffraction effects modify the spatial properties of the focused radial Laguerre-Gauss beams according to their radial mode number p [43]. As an example, we show in Figure 5 the variation of the trap frequencies at the bottom of the trap for the two light field distributions E 0 and E Σ as a function of the objective lens filling factor F 0 within the vectorial Debye propagation model [31,32].…”