采用深紫外光刻及等离子体刻蚀等工艺制备基于绝缘体上硅材料的环形滤波器,且微环半径仅为5μm。制备基于单微环的4通道光分插复用器,器件尺寸仅为3000μm×500μm。测试结果表明,该器件可以很好地实现上下载功能。其自由频谱宽度约...采用深紫外光刻及等离子体刻蚀等工艺制备基于绝缘体上硅材料的环形滤波器,且微环半径仅为5μm。制备基于单微环的4通道光分插复用器,器件尺寸仅为3000μm×500μm。测试结果表明,该器件可以很好地实现上下载功能。其自由频谱宽度约为19.6 nm,最大消光比为19.76 d B。同时优化设计制备基于跑道型双微环可调谐光分插复用器。对这两种结构的光分插复用器的相邻信道间串扰进行测试,基于单微环滤波器和跑道型双微环滤波器的信道间最大串扰分别为-11.94 d B和-20.04 d B。所设计的基于双微环光分插复用器上下载通道与主信道间没有交叉波导结构,因此相邻通道串扰明显低于单环型的光分插复用器。同时设计并制备基于双微环PIN结型电光调制器。当偏置电压增加到1.6 V时,谐振峰发生0.78 nm的蓝移,并对测试结果进行分析。展开更多
The coupling between optical and mechanical degrees of freedom has been of broad interest for a long time. However, it is only until recently, with the rapid development of optical mierocavity research, that we are ab...The coupling between optical and mechanical degrees of freedom has been of broad interest for a long time. However, it is only until recently, with the rapid development of optical mierocavity research, that we are able to manipulate and utilize this coupling process. When a high Q microeavity couples to a mechanical resonator, they can consolidate into an optomeehanieal system. Benefitting from the unique characteristics offered by optomeehanical coupling, this hybrid system has become a promising platform for ultrasensitive sensors to detect displacement, mass, force and acceleration. In this review, we introduce the basic physical concepts of cavity optomechanies, and describe some of the most typical experimental cavity optomechanical systems for sensing applications. Finally, we discuss the noise arising from various sources and show the potentiality of optomechanical sensing towards quantum-noise-limited detection.展开更多
An ultrasensitive metamaterial sensor based on double-slot vertical split ring resonators(DVSRRs) is designed and numerically calculated in the terahertz frequency. This DVSRR design produces a fundament LC resonance ...An ultrasensitive metamaterial sensor based on double-slot vertical split ring resonators(DVSRRs) is designed and numerically calculated in the terahertz frequency. This DVSRR design produces a fundament LC resonance with a quality factor of about 20 when the incidence magnetic field component normal to the DVSRR array. The resonant characteristics and sensing performance of the DVSRR array design are systematically analyzed employing a contrast method among three similar vertical split ring resonator(SRRs) structures. The research results show that the elimination of bianisotropy, induced by the structural symmetry of the DVSRR design, helps to achieve LC resonance of a high quality factor. Lifting the SRRs up from the substrate sharply reduces the dielectric loss introduced by the substrate. All these factors jointly result in superior sensitivity of the DVSRR to the attributes of analytes. The maximum refractive index sensitivity is 788 GHz/RIU or 1.04 × 10~5 nm∕RIU.Also, the DVSRR sensor maintains its superior sensing performance for fabrication tolerance ranging from -4% to 4% and wide range incidence angles up to 50° under both TE and TM illuminations.展开更多
Wide dynamic range is an important index of the resonator fiber optic gyro（RFOG）. The dynamic range is related to the parameters of the fiber ring resonator（FRR）. After adopting the appropriate parameters, the res...Wide dynamic range is an important index of the resonator fiber optic gyro（RFOG）. The dynamic range is related to the parameters of the fiber ring resonator（FRR）. After adopting the appropriate parameters, the resonant curve of a FRR and the synchronous demodulated curve are measured. Based on the closed-loop frequency locking technique, the wide dynamic range is obtained, while the linearity is guaranteed. The experiment’s results show that the dynamic range is 480 deg ∕s with less than 1% nonlinearity, and that the bias stability is0.04 deg/s over 2000 s. This Letter demonstrates the scheme for a RFOG with a wide dynamic range.展开更多
Noise reduction for aircraft engine has attracted great concern due to the strict noise control regulation nowadays. Conventional perforated sheet-over-honeycomb acoustic liners have been widely used to attenuate turb...Noise reduction for aircraft engine has attracted great concern due to the strict noise control regulation nowadays. Conventional perforated sheet-over-honeycomb acoustic liners have been widely used to attenuate turbofan engine noise. To dampen the broadband noise and resist the harsh service conditions with high temperature and pressure in modern turbofan engine,new acoustic liner concepts are proposed and evaluated in the latest decade. In this review,available studies regarding the recent development of liners are gathered. The paper starts with the introduction of acoustic absorption mechanism of local-reacting and extended-reacting liners. The progress of novel passive liners(e.g.,mesh-cap liner,variable-depth liner,metal foam liner,hybrid liner,etc.) is summarized. Furthermore,adaptive liners with tunable geometry dimension or bias flow are illustrated in details.Metamaterial is also mentioned as a hot candidate in the next generation of acoustic liners. Finally,this review identifies benefits and some technical challenges with the goal of unveiling the potential of novel acoustic liner technologies in aero engine.展开更多
In a diode-pumped, KTP intracavity frequency-doubled green laser, multi-Brewster plates are used to achieve high power single-frequency operation. With a simple experimental setup, single-frequency operation of the di...In a diode-pumped, KTP intracavity frequency-doubled green laser, multi-Brewster plates are used to achieve high power single-frequency operation. With a simple experimental setup, single-frequency operation of the diode-pumped green laser with output of 46 and 218 mW is obtained by one and three Brewster plate, respectively.展开更多
Fiber Bragg grating Fabry-Perot (FBG F-P) cavity is used as the sensing model to measure the refractive index of the liquid solution. The cladding of the fiber, which is used as the F-P cavity, is etched by HF solutio...Fiber Bragg grating Fabry-Perot (FBG F-P) cavity is used as the sensing model to measure the refractive index of the liquid solution. The cladding of the fiber, which is used as the F-P cavity, is etched by HF solution to enhance the sensitivity to the external refractive index. The experimental results show that with the concentration change of the external solution, the effective refractive index of etched fiber will change, thus the spectra of FBG F-P cavity will appear a spilt point. The relationship be...展开更多
An erbium-doped fiber （EDF） laser was configured with a fiber grating, a fiber ring resonator, and a saturable absorber by using un-pumped EDF as mode selection element. The laser showed single mode operation with a...An erbium-doped fiber （EDF） laser was configured with a fiber grating, a fiber ring resonator, and a saturable absorber by using un-pumped EDF as mode selection element. The laser showed single mode operation with a narrow linewidth of 5 kHz. The mode selection mechanisms of the un-pumped EDF and the ring resonator are theoretically and experimentally analyzed.展开更多
A new resonator design for doubly resonant continuous-wave （CW） intracavity sum-frequency mixing （SFM） is reported. 1.12 W of coherent radiation at 588 nm is generated by mixing 1062-nm Nd：GdVO4 laser and 1319-nm...A new resonator design for doubly resonant continuous-wave （CW） intracavity sum-frequency mixing （SFM） is reported. 1.12 W of coherent radiation at 588 nm is generated by mixing 1062-nm Nd：GdVO4 laser and 1319-nm Nd：YAG laser. The optical-to-optical conversion efficiency is up to 3.7%.展开更多
High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching...High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.展开更多
According to the vectorial structure of non-paraxial electromagnetic beams and the method of stationary phase, the analytical TE and TM terms of non-paraxial linearly polarized Caussian beam are presented in the far f...According to the vectorial structure of non-paraxial electromagnetic beams and the method of stationary phase, the analytical TE and TM terms of non-paraxial linearly polarized Caussian beam are presented in the far field. The influence of linearly polarized angle on the relative energy flux distributions of the whole beam and its TE and TM terms is studied. The beam spot of the TE term is perpendicular to the direction of linearly polarized angle, while that of the TM term coincides with the direction of linearly polarized angle. The whole beam spot is elliptical, and the long axis is located at the direction of linearly polarized angle. The relative energy flux distribution of the TE term is relatively centralized in the direction perpendicular to the linearly polarized angle. While that of the TM term is relatively centralized in the direction of linearly polarized angle. To obtain the isolated TM and TE terms, a polarizer should be put at the long and the short axis of the whole beam spot, respectively.展开更多
文摘采用深紫外光刻及等离子体刻蚀等工艺制备基于绝缘体上硅材料的环形滤波器,且微环半径仅为5μm。制备基于单微环的4通道光分插复用器,器件尺寸仅为3000μm×500μm。测试结果表明,该器件可以很好地实现上下载功能。其自由频谱宽度约为19.6 nm,最大消光比为19.76 d B。同时优化设计制备基于跑道型双微环可调谐光分插复用器。对这两种结构的光分插复用器的相邻信道间串扰进行测试,基于单微环滤波器和跑道型双微环滤波器的信道间最大串扰分别为-11.94 d B和-20.04 d B。所设计的基于双微环光分插复用器上下载通道与主信道间没有交叉波导结构,因此相邻通道串扰明显低于单环型的光分插复用器。同时设计并制备基于双微环PIN结型电光调制器。当偏置电压增加到1.6 V时,谐振峰发生0.78 nm的蓝移,并对测试结果进行分析。
文摘The coupling between optical and mechanical degrees of freedom has been of broad interest for a long time. However, it is only until recently, with the rapid development of optical mierocavity research, that we are able to manipulate and utilize this coupling process. When a high Q microeavity couples to a mechanical resonator, they can consolidate into an optomeehanieal system. Benefitting from the unique characteristics offered by optomeehanical coupling, this hybrid system has become a promising platform for ultrasensitive sensors to detect displacement, mass, force and acceleration. In this review, we introduce the basic physical concepts of cavity optomechanies, and describe some of the most typical experimental cavity optomechanical systems for sensing applications. Finally, we discuss the noise arising from various sources and show the potentiality of optomechanical sensing towards quantum-noise-limited detection.
基金National Natural Science Foundation of China(NSFC)(61327006,61620106014)
文摘An ultrasensitive metamaterial sensor based on double-slot vertical split ring resonators(DVSRRs) is designed and numerically calculated in the terahertz frequency. This DVSRR design produces a fundament LC resonance with a quality factor of about 20 when the incidence magnetic field component normal to the DVSRR array. The resonant characteristics and sensing performance of the DVSRR array design are systematically analyzed employing a contrast method among three similar vertical split ring resonator(SRRs) structures. The research results show that the elimination of bianisotropy, induced by the structural symmetry of the DVSRR design, helps to achieve LC resonance of a high quality factor. Lifting the SRRs up from the substrate sharply reduces the dielectric loss introduced by the substrate. All these factors jointly result in superior sensitivity of the DVSRR to the attributes of analytes. The maximum refractive index sensitivity is 788 GHz/RIU or 1.04 × 10~5 nm∕RIU.Also, the DVSRR sensor maintains its superior sensing performance for fabrication tolerance ranging from -4% to 4% and wide range incidence angles up to 50° under both TE and TM illuminations.
基金supported by the National Natural Science Foundation of China under Grant Nos.51225504,91123036,61178058,and 61275166
文摘Wide dynamic range is an important index of the resonator fiber optic gyro（RFOG）. The dynamic range is related to the parameters of the fiber ring resonator（FRR）. After adopting the appropriate parameters, the resonant curve of a FRR and the synchronous demodulated curve are measured. Based on the closed-loop frequency locking technique, the wide dynamic range is obtained, while the linearity is guaranteed. The experiment’s results show that the dynamic range is 480 deg ∕s with less than 1% nonlinearity, and that the bias stability is0.04 deg/s over 2000 s. This Letter demonstrates the scheme for a RFOG with a wide dynamic range.
文摘Noise reduction for aircraft engine has attracted great concern due to the strict noise control regulation nowadays. Conventional perforated sheet-over-honeycomb acoustic liners have been widely used to attenuate turbofan engine noise. To dampen the broadband noise and resist the harsh service conditions with high temperature and pressure in modern turbofan engine,new acoustic liner concepts are proposed and evaluated in the latest decade. In this review,available studies regarding the recent development of liners are gathered. The paper starts with the introduction of acoustic absorption mechanism of local-reacting and extended-reacting liners. The progress of novel passive liners(e.g.,mesh-cap liner,variable-depth liner,metal foam liner,hybrid liner,etc.) is summarized. Furthermore,adaptive liners with tunable geometry dimension or bias flow are illustrated in details.Metamaterial is also mentioned as a hot candidate in the next generation of acoustic liners. Finally,this review identifies benefits and some technical challenges with the goal of unveiling the potential of novel acoustic liner technologies in aero engine.
基金This work was supported by the National Hi-Tech 863 Project of China under Grant No.2002AA3lll41.
文摘In a diode-pumped, KTP intracavity frequency-doubled green laser, multi-Brewster plates are used to achieve high power single-frequency operation. With a simple experimental setup, single-frequency operation of the diode-pumped green laser with output of 46 and 218 mW is obtained by one and three Brewster plate, respectively.
基金supported by the National Nature Scien- ce Foundation of China (Grant No.60672015).
文摘Fiber Bragg grating Fabry-Perot (FBG F-P) cavity is used as the sensing model to measure the refractive index of the liquid solution. The cladding of the fiber, which is used as the F-P cavity, is etched by HF solution to enhance the sensitivity to the external refractive index. The experimental results show that with the concentration change of the external solution, the effective refractive index of etched fiber will change, thus the spectra of FBG F-P cavity will appear a spilt point. The relationship be...
文摘An erbium-doped fiber （EDF） laser was configured with a fiber grating, a fiber ring resonator, and a saturable absorber by using un-pumped EDF as mode selection element. The laser showed single mode operation with a narrow linewidth of 5 kHz. The mode selection mechanisms of the un-pumped EDF and the ring resonator are theoretically and experimentally analyzed.
基金This work was supported by the Foundation Research Program for National Defense of Commission of Science Technology and Industry for National Defense of China under Grant No.A3620060122.
文摘A new resonator design for doubly resonant continuous-wave （CW） intracavity sum-frequency mixing （SFM） is reported. 1.12 W of coherent radiation at 588 nm is generated by mixing 1062-nm Nd：GdVO4 laser and 1319-nm Nd：YAG laser. The optical-to-optical conversion efficiency is up to 3.7%.
基金support from the National Key Research and Development Program of China (2020YFA0714504,2019YFA0709100).
文摘High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.
文摘According to the vectorial structure of non-paraxial electromagnetic beams and the method of stationary phase, the analytical TE and TM terms of non-paraxial linearly polarized Caussian beam are presented in the far field. The influence of linearly polarized angle on the relative energy flux distributions of the whole beam and its TE and TM terms is studied. The beam spot of the TE term is perpendicular to the direction of linearly polarized angle, while that of the TM term coincides with the direction of linearly polarized angle. The whole beam spot is elliptical, and the long axis is located at the direction of linearly polarized angle. The relative energy flux distribution of the TE term is relatively centralized in the direction perpendicular to the linearly polarized angle. While that of the TM term is relatively centralized in the direction of linearly polarized angle. To obtain the isolated TM and TE terms, a polarizer should be put at the long and the short axis of the whole beam spot, respectively.
