Low-loss, wide-angle Y splitter at ∼16-µm wavelengths built with a two-dimensional photonic crystal

We report a successful experimental realization of a photonic-crystal Y splitter operating at $\lambda \sim 1.6 \mathit{\mu }\mathrm{m}$. Our device has a large splitting angle of 120° and a miniature size of $\sim 3 \mathit{\mu }\mathrm{m}\times 3 \mathit{\mu }\mathrm{m}$. Furthermore, the Y-splitter loss is measured to be 0.5–1 dB at $\lambda =1640–1680 \mathrm{nm}$, making the Y splitter promising for integrated photonic-circuit applications. These unique properties are attributed to the new guiding principle made possible by the photonic bandgap.