For speckle-correlation-based scattering imaging,an iris is generally used next to the diffuser to magnify the speckle size and enhance the speckle contrast,which limits the light flux and makes the setup cooperative....For speckle-correlation-based scattering imaging,an iris is generally used next to the diffuser to magnify the speckle size and enhance the speckle contrast,which limits the light flux and makes the setup cooperative.Here,we experimentally demonstrate a non-iris speckle-correlation imaging method associated with an image resizing process.The experimental results demonstrate that,by estimating an appropriate resizing factor,our method can achieve high-fidelity noncooperative speckle-correlation imaging by digital resizing of the raw captions or on-chip pixel binning without iris.The method opens a new door for noncooperative high-frame-rate speckle-correlation imaging and benefits scattering imaging for dynamic objects hidden behind opaque barriers.展开更多
Microring resonators (MRRs) with ultracompact footprints are preferred for enhancing the light-matter interactions to benefit various applications. Here,ultracompact titanium dioxide (TiO2) MRRs with sub-10-μm radii ...Microring resonators (MRRs) with ultracompact footprints are preferred for enhancing the light-matter interactions to benefit various applications. Here,ultracompact titanium dioxide (TiO2) MRRs with sub-10-μm radii are experimentally demonstrated. Thanks to the large refractive index of TiO_(2),the quality factors up to -7.9×10^(4) and -4.4×10^(4)are achieved for TiO_(2) MRRs with radii of 10μm and 6μm,respectively,which result in large nonlinear power enhancement factors (>113) and large Purcell factors (>56). The four-wave mixing(FWM) measurements indicate that,compared to the large MRR,the FWM conversion efficiency of the ultracompact TiO2 MRRs can be greatly improved (e.g.,-25 dB versus-31 dB),a harbinger of significant superiorities. Demonstrations in this work provide more arguments for the TiO_(2) waveguides as a promising platform for various on-chip photonic devices.展开更多
基金supported by the National Natural Science Foundation of China(No.62005317)the National Key R&D Program of China(No.2020YFA0713504)the Natural Science Foundation of Hunan Province,China(No.2021JJ40695)。
文摘For speckle-correlation-based scattering imaging,an iris is generally used next to the diffuser to magnify the speckle size and enhance the speckle contrast,which limits the light flux and makes the setup cooperative.Here,we experimentally demonstrate a non-iris speckle-correlation imaging method associated with an image resizing process.The experimental results demonstrate that,by estimating an appropriate resizing factor,our method can achieve high-fidelity noncooperative speckle-correlation imaging by digital resizing of the raw captions or on-chip pixel binning without iris.The method opens a new door for noncooperative high-frame-rate speckle-correlation imaging and benefits scattering imaging for dynamic objects hidden behind opaque barriers.
基金Danish Council for Independent Research (DFF-7107-00242)Villum Fonden (00023316)+2 种基金National Natural Science Foundation of China (62005317)Natural Science Foundation of Hunan Province (2019JJ40341)China Scholarship Council (201803170195)。
文摘Microring resonators (MRRs) with ultracompact footprints are preferred for enhancing the light-matter interactions to benefit various applications. Here,ultracompact titanium dioxide (TiO2) MRRs with sub-10-μm radii are experimentally demonstrated. Thanks to the large refractive index of TiO_(2),the quality factors up to -7.9×10^(4) and -4.4×10^(4)are achieved for TiO_(2) MRRs with radii of 10μm and 6μm,respectively,which result in large nonlinear power enhancement factors (>113) and large Purcell factors (>56). The four-wave mixing(FWM) measurements indicate that,compared to the large MRR,the FWM conversion efficiency of the ultracompact TiO2 MRRs can be greatly improved (e.g.,-25 dB versus-31 dB),a harbinger of significant superiorities. Demonstrations in this work provide more arguments for the TiO_(2) waveguides as a promising platform for various on-chip photonic devices.
