Fig. 3: Birefringence laser patterns written with different ellipticities and energies.
From: Efficient ultrafast laser writing with elliptical polarization
a Birefringence and b scanning electron microscope (SEM) image of the region imprinted by linearly (top) and elliptically (bottom) polarized laser pulses with a duration of 600 fs and energy of 0.9 μJ. c and d Retardance of birefringent modification versus ellipticity with pulse duration of 600 fs and 300 fs. Writing conditions: 10 mm/s scanning speed, 200 kHz repetition rate, 1030 nm wavelength, 0.16 NA lens
