부산대학교 도서관

Photonic integrated circuits (PICs) are expected to add practicality and new functionalities in a considerable number of optical applications, including optical microscopy. Here, we present a PIC design allowing a far-field structured UV illumination pattern with a fringe period as low as $\text{370}\,\text{nm}$, a fringe visibility of 0.83 over field of views of more than $150\,\mu \text{m}\,\times 200\,\mu \text{m}$ and a radiant intensity as large as $\text{0.49}\,\text{mW}$. The circuits include single mode waveguides with propagation losses of $\text{3}\,\text{dB/cm}$ at a wavelength $\lambda =360\,\text{nm}$, two diffraction gratings for beam shaping out of the chip plane, a beam splitter and a phase shifter. Using fluorescent gratings with pitches longer or shorter than the wavelength, as control objects, and a collecting lens with a numerical aperture of 0.5, the current PICs enable to highlight experimentally the Moiré pattern at the heart of the optical resolution enhancement and to achieve a doubling of the optical resolution in the direction of the illumination.