Fig. 1. (a) The liquid jet system: the two nozzles forming the sheet and elements of the thickness measuring arrangement, that is, the condensing and collimating lenses and the optical fiber and (b) the logical diagram of the liquid jet circuit.

Fig. 2. Formation of the top liquid leaf: (a) side view; (b) front view.

Fig. 3. Measurement of the liquid leaf’s position stability with the Micro-Epsilon® system. The leaf was produced with nozzles of (a) 10 μm and (b) 18 μm orifices, and flowrates of 0.50 and 1.27 mL/min, respectively.

Fig. 4. The mean value of displacement as a function of the flowrate for orifice sizes of (a) 10 μm and (b) 18 μm. The error bar represents the standard deviation of three independent measurements.

Fig. 5. Displacement of the liquid sheet generated by periodic laser pulses for various orifice sizes as a function of the laser’s repetition rate. (The lines are only to guide the eye.)

Fig. 6. Schematic of the optical arrangement for thickness measurement in vacuum ambient operation (top view).

Fig. 7. Measured spectral transmittance with the fitted curve of a PET foil.

Fig. 8. The thickness variation along the vertical axis (a) of the liquid leaf at different flowrates of water (orifice size): (b) 10 μm, (c) 11 μm and (d) 18 μm. The measured and evaluated spectral interference fringes are shown for the two thinnest values of 182 nm (e) and 212 nm (f). The error of the measurement was 3%.

Fig. 9. Thickness of the liquid leaf at a certain point on the vertical symmetry axis as a function of the flowrate (10 μm orifice size).

Fig. 10. Grid of the measured thicknesses (stars) lying on the calculated thickness profile of the liquid leaf (10 μm orifice size and 0.54 mL/min flowrate).

Fig. 11. The thickness variation with the ambient pressure at a given point of the symmetry axis of the liquid leaf at a flowrate of 0.7 mL/min.

Fig. 12. The measured thickness of the liquid sheet at a flowrate of 0.7 mL/min in air (black) and in vacuum (red) in cases of the 11 and 18 μm orifices.

Fig. 13. Endurance test results of the continuously working liquid jet. The data show the required rollback angle to the original direction of the liquid leaf, using the reflected light during the experiment.