We give a brief review of the developments in terahertz time-domain spectroscopy(THz-TDS) systems and microcavity components for probing samples in the University of Shanghai for Science and Technology. The broadband ...We give a brief review of the developments in terahertz time-domain spectroscopy(THz-TDS) systems and microcavity components for probing samples in the University of Shanghai for Science and Technology. The broadband terahertz(THz) radiation sources based on GaAs m-i-n diodes have been investigated by applying high electric fields. Then, the free space THz-TDS and fiber-coupled THz-TDS systems produced in our lab and their applications in drug/cancer detection are introduced in detail. To further improve the signal-to-noise ratio(SNR) and enhance sensitivity, we introduce three general micro-cavity approaches to achieve tiny-volume sample detection, summarizing our previous results about their characteristics, performance, and potential applications.展开更多
This article presents an in-depth exploration of the acoustofluidic capabilities of guided flexural waves(GFWs)generated by a membrane acoustic waveguide actuator(MAWA).By harnessing the potential of GFWs,cavity-agnos...This article presents an in-depth exploration of the acoustofluidic capabilities of guided flexural waves(GFWs)generated by a membrane acoustic waveguide actuator(MAWA).By harnessing the potential of GFWs,cavity-agnostic advanced particle manipulation functions are achieved,unlocking new avenues for microfluidic systems and lab-on-a-chip development.The localized acoustofluidic effects of GFWs arising from the evanescent nature of the acoustic fields they induce inside a liquid medium are numerically investigated to highlight their unique and promising characteristics.Unlike traditional acoustofluidic technologies,the GFWs propagating on the MAWA’s membrane waveguide allow for cavity-agnostic particle manipulation,irrespective of the resonant properties of the fluidic chamber.Moreover,the acoustofluidic functions enabled by the device depend on the flexural mode populating the active region of the membrane waveguide.Experimental demonstrations using two types of particles include in-sessile-droplet particle transport,mixing,and spatial separation based on particle diameter,along with streaming-induced counter-flow virtual channel generation in microfluidic PDMS channels.These experiments emphasize the versatility and potential applications of the MAWA as a microfluidic platform targeted at lab-on-a-chip development and showcase the MAWA’s compatibility with existing microfluidic systems.展开更多
Integrated optomechanical crystal(OMC)cavities provide a vital device prototype for highly efficient microwave to optical conversion in quantum information processing.In this work,we propose a novel heterogeneous OMC ...Integrated optomechanical crystal(OMC)cavities provide a vital device prototype for highly efficient microwave to optical conversion in quantum information processing.In this work,we propose a novel heterogeneous OMC cavity consisting of a thin-film lithium niobate(TFLN)slab and chalcogenide(ChG)photonic crystal nanobeam coupled by a wavelength-scale mechanical waveguide.The optomechanical coupling rate of the heterogeneous OMC cavity is optimized up to 340 kHz at 1.1197 GHz.Combined with phononic band and power decomposition,17.38%energy from the loaded RF power is converted into dominant fundamental horizontal shear mode(SH0)in the narrow LN mechanical waveguide.Based on this fraction,as a result,3.51%power relative to the loaded RF energy is scattered into the fundamental longitudinal mode(L0)facing the TFLN-ChG heterogeneous waveguide.The acoustic breathing mode of the heterogeneous OMC is successfully excited under the driving of the propagating L0 mode in the heterogeneous waveguide,demonstrating the great potentials of the heterogeneous piezo-optomechanical transducer in high-performance photon–phonon interaction fields.展开更多
We fabricated a new type of two-dimensional photonic crystal slab filter. The resonant cavities were directly put into the waveguide arms. The optical transmissions of the filters were measured and the results show th...We fabricated a new type of two-dimensional photonic crystal slab filter. The resonant cavities were directly put into the waveguide arms. The optical transmissions of the filters were measured and the results show that the optimized two-channel filters give good intensity distribution at the output ports of the waveguide. A minimum wavelength spacing of 5 nm of the filter outputs is realized by accurately controlling the size of the resonant cavities.展开更多
Two substrate integrated waveguide(SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively...Two substrate integrated waveguide(SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively. Firstly, multi-mode resonance theory is employed to broaden the bandwidth of the slot antenna. And then, an SIW cavity composed of 4×4 cornercut elements is added on the top of the slot antenna to achieve the circular polarization and improve the front-to-back ratio. Thirdly, the metasurface elements are sequentially rotated and a high gain antenna with 2-dBi enhancement on average in the operation band is obtained. Based on the two antenna units, two 2×2 antenna arrays are designed. The circularly polarized and high gain antenna arrays are both fabricated to verify the correctness. Furthermore, the novel wideband phase shifter is employed in the circularly polarized antenna to obtain an operating bandwidth of 38%(4.05 GHz–5.95 GHz)and AR bandwidth of 24.9%(4.4 GHz–5.65 GHz). The bandwidth of the high gain antenna can reach 42.7%(3.95 GHz–6.1 GHz) and with the gain enhancement of 2 dBi compared with that of the circularly polarized antenna. The gain remains steady in most of operating band within a variation of 1 dBi. It is remarkable that the rotating of the metasurface element has a great influence on the antenna performance, which provides a new explication for the multi-function antenna design.展开更多
Narrow linewidth light source is a prerequisite for high-performance coherent optical communication and sensing.Waveguide-based external cavity narrow linewidth semiconductor lasers(WEC-NLSLs)have become a competitive...Narrow linewidth light source is a prerequisite for high-performance coherent optical communication and sensing.Waveguide-based external cavity narrow linewidth semiconductor lasers(WEC-NLSLs)have become a competitive and attractive candidate for many coherent applications due to their small size,volume,low energy consumption,low cost and the ability to integrate with other optical components.In this paper,we present an overview of WEC-NLSLs from their required technologies to the state-of-the-art progress.Moreover,we highlight the common problems occurring to current WEC-NLSLs and show the possible approaches to resolving the issues.Finally,we present the possible development directions for the next phase and hope this review will be beneficial to the advancements of WEC-NLSLs.展开更多
An S-band cavity BPM is designed for a new injector in National Synchrotron Radiation Laboratory. A re-entrant position cavity is tuned to the TM110 mode as position cavity. Cut-through waveguides are used as pickups ...An S-band cavity BPM is designed for a new injector in National Synchrotron Radiation Laboratory. A re-entrant position cavity is tuned to the TM110 mode as position cavity. Cut-through waveguides are used as pickups to suppress the monopole signal. Theoretical resolution of this design is 31 nm. A prototype cavity BPM system is manufactured for off-line cold tests. The wire scanning method is used to calibrate the BPM and estimate the performance of the on-line BPM system. A cross-talk problem has been detected during the cold test. Racetrack cavity BPM design can be used to suppress the cross-talk. With the nonlinear effect being ignored, transform matrix can be used to correct cross-talk. Analysis of cold test results shows that the position resolution of prototype BPM is better than 3 μm.展开更多
基金the National Key R&D Program of China (No. 2018YFF01013003)the Program of Shanghai Pujiang Program, China (No. 17PJD028)+4 种基金the National Natural Science Foundation of China (Nos. 61671302, 61601291, and 61722111)the Shuguang Program supported by the Shanghai Education Development Foundation and Shanghai Municipal Education Commission, China (No. 18SG44)the Key Scientific and Technological Project of Science and Technology Commission of Shanghai Municipality, China (No. 15DZ0500102)the Shanghai Leading Talent, China (No. 2016-019)the Young Yangtse Rive Scholar, China (No. Q2016212).
文摘We give a brief review of the developments in terahertz time-domain spectroscopy(THz-TDS) systems and microcavity components for probing samples in the University of Shanghai for Science and Technology. The broadband terahertz(THz) radiation sources based on GaAs m-i-n diodes have been investigated by applying high electric fields. Then, the free space THz-TDS and fiber-coupled THz-TDS systems produced in our lab and their applications in drug/cancer detection are introduced in detail. To further improve the signal-to-noise ratio(SNR) and enhance sensitivity, we introduce three general micro-cavity approaches to achieve tiny-volume sample detection, summarizing our previous results about their characteristics, performance, and potential applications.
基金supported by A*STAR under the“Nanosystems at the Edge”programme(Grant No.A18A4b0055).
文摘This article presents an in-depth exploration of the acoustofluidic capabilities of guided flexural waves(GFWs)generated by a membrane acoustic waveguide actuator(MAWA).By harnessing the potential of GFWs,cavity-agnostic advanced particle manipulation functions are achieved,unlocking new avenues for microfluidic systems and lab-on-a-chip development.The localized acoustofluidic effects of GFWs arising from the evanescent nature of the acoustic fields they induce inside a liquid medium are numerically investigated to highlight their unique and promising characteristics.Unlike traditional acoustofluidic technologies,the GFWs propagating on the MAWA’s membrane waveguide allow for cavity-agnostic particle manipulation,irrespective of the resonant properties of the fluidic chamber.Moreover,the acoustofluidic functions enabled by the device depend on the flexural mode populating the active region of the membrane waveguide.Experimental demonstrations using two types of particles include in-sessile-droplet particle transport,mixing,and spatial separation based on particle diameter,along with streaming-induced counter-flow virtual channel generation in microfluidic PDMS channels.These experiments emphasize the versatility and potential applications of the MAWA as a microfluidic platform targeted at lab-on-a-chip development and showcase the MAWA’s compatibility with existing microfluidic systems.
基金National Natural Science Foundation of China(62175095,U2001601,61935013)。
文摘Integrated optomechanical crystal(OMC)cavities provide a vital device prototype for highly efficient microwave to optical conversion in quantum information processing.In this work,we propose a novel heterogeneous OMC cavity consisting of a thin-film lithium niobate(TFLN)slab and chalcogenide(ChG)photonic crystal nanobeam coupled by a wavelength-scale mechanical waveguide.The optomechanical coupling rate of the heterogeneous OMC cavity is optimized up to 340 kHz at 1.1197 GHz.Combined with phononic band and power decomposition,17.38%energy from the loaded RF power is converted into dominant fundamental horizontal shear mode(SH0)in the narrow LN mechanical waveguide.Based on this fraction,as a result,3.51%power relative to the loaded RF energy is scattered into the fundamental longitudinal mode(L0)facing the TFLN-ChG heterogeneous waveguide.The acoustic breathing mode of the heterogeneous OMC is successfully excited under the driving of the propagating L0 mode in the heterogeneous waveguide,demonstrating the great potentials of the heterogeneous piezo-optomechanical transducer in high-performance photon–phonon interaction fields.
基金Project supported by the National Key Basic Research and Development Programme of China （Grant No 2001CB6104）, the National Center for Nanoscience and Technology, China （Grant No 2003CB7169） and the National Natural Science Foundation of China （Grant No 10474036）.
文摘We fabricated a new type of two-dimensional photonic crystal slab filter. The resonant cavities were directly put into the waveguide arms. The optical transmissions of the filters were measured and the results show that the optimized two-channel filters give good intensity distribution at the output ports of the waveguide. A minimum wavelength spacing of 5 nm of the filter outputs is realized by accurately controlling the size of the resonant cavities.
基金Project supported by the National Natural Science Foundation of China (Grant No.61871394)。
文摘Two substrate integrated waveguide(SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively. Firstly, multi-mode resonance theory is employed to broaden the bandwidth of the slot antenna. And then, an SIW cavity composed of 4×4 cornercut elements is added on the top of the slot antenna to achieve the circular polarization and improve the front-to-back ratio. Thirdly, the metasurface elements are sequentially rotated and a high gain antenna with 2-dBi enhancement on average in the operation band is obtained. Based on the two antenna units, two 2×2 antenna arrays are designed. The circularly polarized and high gain antenna arrays are both fabricated to verify the correctness. Furthermore, the novel wideband phase shifter is employed in the circularly polarized antenna to obtain an operating bandwidth of 38%(4.05 GHz–5.95 GHz)and AR bandwidth of 24.9%(4.4 GHz–5.65 GHz). The bandwidth of the high gain antenna can reach 42.7%(3.95 GHz–6.1 GHz) and with the gain enhancement of 2 dBi compared with that of the circularly polarized antenna. The gain remains steady in most of operating band within a variation of 1 dBi. It is remarkable that the rotating of the metasurface element has a great influence on the antenna performance, which provides a new explication for the multi-function antenna design.
基金Jiangsu Province Key R&D Program(Industry Prospect and Common Key Technologies)(No.BE2014083)Jiangxi Natural Science Foundation Project(No.2019ACBL20054)。
文摘Narrow linewidth light source is a prerequisite for high-performance coherent optical communication and sensing.Waveguide-based external cavity narrow linewidth semiconductor lasers(WEC-NLSLs)have become a competitive and attractive candidate for many coherent applications due to their small size,volume,low energy consumption,low cost and the ability to integrate with other optical components.In this paper,we present an overview of WEC-NLSLs from their required technologies to the state-of-the-art progress.Moreover,we highlight the common problems occurring to current WEC-NLSLs and show the possible approaches to resolving the issues.Finally,we present the possible development directions for the next phase and hope this review will be beneficial to the advancements of WEC-NLSLs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10875117 and 11005106)National "985 Project" (Grnat No. 173123200402002)+1 种基金China Postdoctoral Science Foundation (Grant No. 20100470853)"the Fundamental Research Funds for the Central Universities"
文摘An S-band cavity BPM is designed for a new injector in National Synchrotron Radiation Laboratory. A re-entrant position cavity is tuned to the TM110 mode as position cavity. Cut-through waveguides are used as pickups to suppress the monopole signal. Theoretical resolution of this design is 31 nm. A prototype cavity BPM system is manufactured for off-line cold tests. The wire scanning method is used to calibrate the BPM and estimate the performance of the on-line BPM system. A cross-talk problem has been detected during the cold test. Racetrack cavity BPM design can be used to suppress the cross-talk. With the nonlinear effect being ignored, transform matrix can be used to correct cross-talk. Analysis of cold test results shows that the position resolution of prototype BPM is better than 3 μm.
