Researchers at Peking University’s Femtosecond Photophysics and Integrated Optics division have developed an integrated all-optical diode with very high transmission and very low power characteristics.
The paper on integrated optics research has been titled Low-Power and High-contrast Nanoscale All-Optical Diodes via Nanocomposite Photonic Crystal Microcavities and will be published in Advanced Functional Materials.
The researchers made the observation after the completing the all-optical switch equipment with high-speed photonic crystal and very low power.
The all-optical photonic crystal (PC) diode can be applied in the fields of optical interconnection systems, optical computing and integrated photonic circuits. Its features include a high transmission contrast and a low operating power. The high operating threshold power along with high threshold intensity is due to traditional optical materials’ negligible non-linear optical coefficient. In addition, the low transmission contrast makes the diodes unsuitable for practical applications.
The researchers combined the photonic crystal microcavity’s photon confinement effect with the plasmonic response of metal nanoparticles to develop a nanocomposite PC microcavity with high nonlinear susceptibilities of the third order.
A model of all-optical PC diode is created based on the coupling of irregular microcavity modes and the surface-plasmon resonance effect, which improves optical non-linearity. A high transmission contrast of 11875 and a threshold photon intensity of only 2.1 MW/cm2 can be achieved at the same time. Thus, the findings will advance the practical application research on all-optical diodes and will offer a new dimension to study optical material.
The research is supported by the National Nature Science foundation of China and the National Basic Research Program of China (973 Program).