Figure 1 | Scientific Reports

Figure 1

From: Bessel beam CARS of axially structured samples

Figure 1

Experimental Setup: Employing the Ti:Sapphire laser directly as Stokes beam its size is reduced to build a weakly focused Gaussian beam after the focusing objective.

The pump laser generated by an optic parametric oscillator (OPO) is reshaped by a 6 lenses combination that transforms the incoming Gaussian beam into a narrow (D/d ≥ 10) collimated laser ring. The insertion in the green box visualizes the ring formation. First, a beam expander increases the beam width. The laser is refracted by the first axicon onto a cone. The second axicon collimates the laser. Preserving the ratio D/d the beam reducer decreases the ring size to meet the back aperture of the following objective lens. ① Ti:Sa-Laser; ② Beam splitter; ③ Optical parametric oscillator (OPO); ④ Camera; ⑤ Bandpass filter; ⑥ Objective lens; ⑦ Sample; ⑧ Combination of a beam expander, double axicon arrangement and beam size reducer; ⑨ Beam combiner.

Back to article page