Figure 1: Programmable Bessel beam excitation.
From: Efficient second-harmonic imaging of collagen in histological slides using Bessel beam excitation
The figure shows the axial and transverse square intensity distribution of beams used in this study (left, simulations; right, camera-based measurements). The wavelengths and FWHM extension of the main lobe of the focused beam correspond to, from top to bottom: (A) (Gaussian) λ = 1100 nm, 1.4 μm × 0.3 μm; (B) λ = 1100 nm, 7 μm × 0.2 μm; (C) λ = 1100 nm, 14 μm × 0.3 μm; (D) λ = 1100 nm, 23 μm × 0.56 μm; (E) λ = 850 nm 23 μm × 0.2 μm. Profiles (bottom) are plotted along the white dotted line. Square intensity scaling factors are indicated for experimental Bessel beams obtained with the same objective and wavelength.
