posted on 2024-08-06, 12:05authored byHua Fan, Meguya Ryu, Reo Honda, Junko Morikawa, Zhen Ze Li, Lei Wang, Jovan Maksimovic, Saulius JuodkazisSaulius Juodkazis, Qi Dai Chen, Hong Bo Sun
Birefringence of 3×10-3 is demonstrated inside cross-sectional regions of 100 µm, inscribed by axially stretched Bessel-beam-like fs-laser pulses along the c-axis inside sapphire. A high birefringence and retardance of λ/4 at mid-visible spectral range (green) can be achieved using stretched beams with axial extension of 30–40 µm. Chosen conditions of laser-writing ensure that there are no formations of self-organized nano-gratings. This method can be adopted for creation of polarization optical elements and fabrication of spatially varying birefringent patterns for optical vortex generation.
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Photonic crystals: The key to breaking the silicon-solar cell efficiency barrier