Controlled thermonuclear reactors require consistent monitoring of plasma in the toroidal chamber.Better working conditions of such machines can be monitored by analyzing its radiations.Various wavelengths such as 656...Controlled thermonuclear reactors require consistent monitoring of plasma in the toroidal chamber.Better working conditions of such machines can be monitored by analyzing its radiations.Various wavelengths such as 656.3,486.1,464.7 nm are quite significant which are used for health monitoring of thermonuclear machines.The optical thinfilmfilters which work on construc-tive and destructive interference are the ideal choices.Thesefilters are multi-layered with a pair of high and low refractive index dielectric materials.Significantly high transmission index at the desired wavelength and relatively low transmission at the other wavelengths are desired.With this as the objective,it is necessary to design thefilter.Various optimization techniques are used for identifying the suitable design of thefilters.To choose the parameter combination that provides the most excellent performance,optimization of the design para-meters is entailed.The goal of this work is to improve the optical bandfilter using the Bald eagle search optimization(BES)method.The ideal design is determined by assessing several characteristics such as thickness,refractive index,Full-Width at Half-Maximum(FWHM),and the impact of choosing optical properties,which increases transmission potential.Initially,an alternate multi-layer stack with 28,30,and 32 layers is created by altering the thickness while keeping the dielectric substances high and low refractive indices constant.By adjusting the thickness of each layer,the BES algorithm achieves the best practical solution.The proposed method is implemented using MATLAB and the outcomes show the efficacy of the proposed technique.The transmittance,reflectance,and FWHM using the pro-posed BES are found to be 99.9356%,0.065%,and 1.2 nm respectively.展开更多
A narrow linewidth Faraday anomalous dispersion optical filter(FADOF)with reflection configuration is achieved for the first time based on the cesium(Cs)ground state 6S_(1/2) to the excited state 6P_(3/2) transition a...A narrow linewidth Faraday anomalous dispersion optical filter(FADOF)with reflection configuration is achieved for the first time based on the cesium(Cs)ground state 6S_(1/2) to the excited state 6P_(3/2) transition at 852 nm.Compared with the conventional FADOF with transmission configuration,reflection-type FADOF can greatly improve the transmittance of optical filter under the same experimental parameters,because it allows signal light to go and return through the atomic vapor cell.In our experiment,peak transmittance at Cs 6S_(1/2) F=4-6P_(3/2) transition is 81%for the reflection-type FADOF,and while 54%for the transmission-type FADOF when the temperature of Cs vapor cell and the axial magnetic field are 60℃and 19 G.The idea of this reflection-type FADOF design has the potential to be applied to the FADOF operating between two excited states to obtain higher transmittance.展开更多
Selective absorptive nanofluid can pre-absorb certain sunlight wavelength that cannot be used by PV and transmits remaining sunlight to the surface of PV,which can decouple PV from the thermal receiver spatially.In or...Selective absorptive nanofluid can pre-absorb certain sunlight wavelength that cannot be used by PV and transmits remaining sunlight to the surface of PV,which can decouple PV from the thermal receiver spatially.In order to improve the harvesting of electricity and high-temperature thermal nanofluid,it is important to design an optimal optical filter window(transmit sunlight with wavelengths of 732-1067 nm to the surface of the photovoltaic cell and absorb the remaining sunlight).However,designing optimal optical filter is facing following challenges:(1) inherently narrow selective absorptivity property of single nanoparticle;(2) simplified numerical calculation method calculating transmittance;(3) ignoring the shape of the nanoparticle.In this study,the idea of using multiple nanoparticles coupling effect to design an optical filter is proposed,which can superimpose the narrow absorption bandwidth of different nanoparticles to obtain a wide absorption bandwidth of the whole system.In addition,an improved transmission method considering light-matter interaction at air/vessel and liquid/vessel interfaces is adopted to compute the transmittance.The results calculated by improved transmission method are more accurate than widely used traditional Lambert-Beer law,which is verified by experimental test.Furthermore,the effect of nanoparticle shape on spectral transmittance is also investigated,which shows that spiny Ag can approximately extend absorbance from 400 nm to 600 nm compared to nanosphere silver.Finally,the results show that optical filter efficiency of nanofluids with multiple nanoparticles coupling(Ag,spiny Ag,ZnO,ITO) can reached up to 35%.展开更多
Optical filters are essential in a wide range of applications,including optical communications,electronics,lighting,optical sensors and photography.This article presents recent work which indicates that optical filter...Optical filters are essential in a wide range of applications,including optical communications,electronics,lighting,optical sensors and photography.This article presents recent work which indicates that optical filters can be created from specialized nanoparticle suspensions.Specifically,this article describes a theoretical optimization process for designing nanofluid-based filters for hybrid solar photovoltaic/thermal(PV/T)applications.This particular application is suitable because nanofluids can be utilized as both volumetric solar absorbers and flowing heat transfer mediums.The nanofluid filters described in this work compare favorably with conventional optical filters for five photovoltaic(PV)cell alternatives:InGaP,CdTe,InGaAs,Si,and Ge.This study demonstrates that nanofluids make efficient,compact and potentially low-cost,spectrally selective optical filters.展开更多
A 459 nm Faraday anomalous dispersion optical filter（FADOF） working at the side wings of the cesium6S1∕2→ 7P1∕2transition with weak oscillator strength is achieved. The transmittance of the higher side wing reach...A 459 nm Faraday anomalous dispersion optical filter（FADOF） working at the side wings of the cesium6S1∕2→ 7P1∕2transition with weak oscillator strength is achieved. The transmittance of the higher side wing reaches 98% at a temperature of 179°C and magnetic field above 323 G. The experimental results coincide with the theoretical predictions in 1982 and 1995, which were not realized in experiments for over three decades. Due to its high transmittance, high accuracy, and narrow linewidth, the 459 nm FADOF can be applied in underwater optical communications, the building of active optical clocks, and laser frequency stabilization in active optical clocks.展开更多
To increase the channel number in the optic filter, the multiple-phase-shift (MPS) technology is adoped based on the multiple-reflection-spectrum-envelopes-concatenation (MRSEC) model which has a broadband flatness. T...To increase the channel number in the optic filter, the multiple-phase-shift (MPS) technology is adoped based on the multiple-reflection-spectrum-envelopes-concatenation (MRSEC) model which has a broadband flatness. The reflection spectra of the MPS digital concatenated sample gratings are simulated with transfer matrix method, the results show that wave band of the reflection spectrum is widened and the channel number is multiplied. What’s more, the spectrum flatness is improved with the increasing of refraction index change. Moreover, to improve the extinction ratio and peak value when MPS is adopted in concatenated SFBG, an available designing method based on the cascaded unit is put forward and the optimized results are obtained.展开更多
A narrowband tunable antireflection optical filter is proposed and numerically studied. The structure is a metasurface based on plasmonic nanoparticles on an electro-optic film in a three-layer configuration of metald...A narrowband tunable antireflection optical filter is proposed and numerically studied. The structure is a metasurface based on plasmonic nanoparticles on an electro-optic film in a three-layer configuration of metaldielectric-metal(MDM) in the visible near-infrared range. By tuning the voltage and thus tuning the refractive index of the dielectric Li Nb O_3, one can shift the wavelength of minimum reflection as desired. The parameters of gold nanoparticles and other elements used for the filter design and refractive index of the dielectric are obtained by the finite-element method(FEM). An analytical theory is presented to explain the FEM simulation results, and they agree well with each other. It is found that the frequency of the plasmonic resonance wave on the metasurface should be equal to that of the Fabry–Perot resonator formed by the MDM to have a good filtering property. Theoretical spectra obtained by FEM simulation show that the structure has extensive potential for the design of tunable narrow-band filters for modulators, displayers, and color extraction for imaging.展开更多
Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by...Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by prevailing methodologies is normally of polycrystalline nature with high nucleation density and limited domain size,which significantly handicaps its overall properties and device performances.Herein,we report an oxygen-assisted CVD strategy to allow the direct synthesis of 6-inch-scale graphene glass harvesting markedly increased graphene domain size(from 0.2 to 1.8μm).Significantly,as-produced graphene glass attains record high electrical conductivity(realizing a sheet resistance of 900Ω·sq^(-1)at a visible-light transmittance of 92%)amongst the state-of-the-art counterparts,readily serving as transparent electrodes for fabricating high-performance optical filter devices.This work might open a new avenue for the scalable production and application of emerging graphene glass materials with high quality and low cost.展开更多
A novel double-channel drop filter of single photons with only a drop waveguide is proposed. In the structure, two microresonators with a qubit are used to connect the drop waveguide and the bus waveguide with a refle...A novel double-channel drop filter of single photons with only a drop waveguide is proposed. In the structure, two microresonators with a qubit are used to connect the drop waveguide and the bus waveguide with a reflector. By tuning the system parameters, multiple wavelengths with high drop efficiencies in two output channels of the drop waveguide are obtained. As the reflector is independent on its exact location, and one drop waveguide with two drop channels saves the integrated space, this may suggest a potential filtering device which functions in photonic integrated circuits and dense wavelength division multiplexing communication.展开更多
In this paper human face machine identification is experienced using optical correlation techniques in spatial frequency domain. This approach is tested on ORL dataset of faces which includes face images of 40 subject...In this paper human face machine identification is experienced using optical correlation techniques in spatial frequency domain. This approach is tested on ORL dataset of faces which includes face images of 40 subjects, each in 10 different positions. The examined optical setup relies on optical correlation based on developing optical Vanderlugt filters and its basics are described in this article. With the limitation of face database of 40 persons, the recognition is examined successfully with nearly 100% of accuracy in matching the input images with their respective Vanderlugt synthesized filters. Software simulation is implemented by using MATLAB for face identification.展开更多
A new four-channel demultiplexer of single photons is proposed, in which four microresonators are utilized to link the four drop waveguides and the bus waveguide. By adjusting the system parameters, the crosstalk effe...A new four-channel demultiplexer of single photons is proposed, in which four microresonators are utilized to link the four drop waveguides and the bus waveguide. By adjusting the system parameters, the crosstalk effect of the multiple channel frequencies is suppressed, and multiple peak frequencies with high drop efficiencies in these output ports are achieved. As the 2 × 2 model is scalable, the proposed structure can provide potential applications in designing scalable optical devices.展开更多
One-dimensional photonic crystals (1D PhCs) have a unique ability to control the propagation of light waves, however certain classes of 1D oxides remain relatively unexplored for use as PhCs. Specifically, there has n...One-dimensional photonic crystals (1D PhCs) have a unique ability to control the propagation of light waves, however certain classes of 1D oxides remain relatively unexplored for use as PhCs. Specifically, there has not been a comparative study of the three different 1D PhC structures to compare the influence of layer thickness, number, and refractive index on the ability of the PhCs to control light transmission. Herein, we use the transfer matrix method (TMM) to theoretically examine the transmission of 1D PhCs composed of layers of TiO<sub>2</sub>/SiO<sub>2</sub>, TiO<sub>2</sub>/SnO<sub>2</sub>, SiO<sub>2</sub>/SnO<sub>2</sub>, and combinations of the three with various top and bottom layer thicknesses to cover a substantial region of the electromagnetic spectrum (UV to NIR). With increasing layer numbers for TiO<sub>2</sub>/SiO<sub>2</sub> and SiO<sub>2</sub>/SnO<sub>2</sub>, the edges became sharper and wider and the photonic bandgap width increased. Moreover, we demonstrated that PhCs with significantly thick TiO<sub>2</sub>/SiO<sub>2</sub> layers had a high transmittance for a wide bandgap, allowing for wide-band optical filter applications. These different PhC architectures could enable a variety of applications, depending on the properties needed.展开更多
Transparent electro-optic(EO)ceramics of La-doped 0.75Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.25PbTiO_(3)(0.75PMN-0.25PT)were prepared successfully.High transparency of 69%in the near-infrared(IR)wavelength(1550 nm)was achieved a...Transparent electro-optic(EO)ceramics of La-doped 0.75Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.25PbTiO_(3)(0.75PMN-0.25PT)were prepared successfully.High transparency of 69%in the near-infrared(IR)wavelength(1550 nm)was achieved at 2 mo1%La doping,meanwhile it shows an extremely high quadratic EO coeficient of 45.4×10^(-16)m^(2)·V^(-2),which s indispensable for applications in EO devices.The distribution of a polar nanodomain structure of the samples experiences disorder-order-disorder evolution in a La doping range.It is found that a parallelly-stacked polar nanodomain structure with an easier and faster polarization switching in the 2 mol%La-doped sample suggests that an ordering distribution of polar nanoregions would be critical to inducing large EO effect,transparency,and piezoelectric response.A triple-cavity tunable optical filter(TOF)with a single transmission peak and a tuning voltage below 30 V in a tuning range of 190-197 THz was designed based on our ceramics.The work is believed to bridge the relationship among doping-engineering,EO properties,and polarization behavior,which would guide the further optimization of transparent EO ceramics.展开更多
GFFs with less than 0.4 dB peak-to-peak error functions are routinely fabricated using commercially available coating machines by utilizing the natural error compensation mechanism of wavelength variable turning point...GFFs with less than 0.4 dB peak-to-peak error functions are routinely fabricated using commercially available coating machines by utilizing the natural error compensation mechanism of wavelength variable turning point optical monitoring method.展开更多
A wavelength filter with simple structure using multimode waveguide is proposed. The device uses mode conversion by a grating structure fabricated simultaneously with the multimode waveguide.
Optical comb filters based on multi-port fused fiber couplers are proposed and numerically analyzed, 3-arm MZI composed by 1×7 fiber splitter and 3×3 fiber coupler, and 2-stage cascaded FIR type MZI interlea...Optical comb filters based on multi-port fused fiber couplers are proposed and numerically analyzed, 3-arm MZI composed by 1×7 fiber splitter and 3×3 fiber coupler, and 2-stage cascaded FIR type MZI interleave filter.展开更多
A novel acousto-optic tunable filter (AOTF) using a hollow optical fiber (HOF) is proposed. Its broadband rejection over 100nm was observed and high polarization dependence as a polarization switch is discussed.
An optical modulation format generation scheme based on spectral filtering and frequency-to-time mapping is experimentally demonstrated. Many modulation formats with continuously adjustable duty radio and bit rate can...An optical modulation format generation scheme based on spectral filtering and frequency-to-time mapping is experimentally demonstrated. Many modulation formats with continuously adjustable duty radio and bit rate can be formed by changing the dispersion of dispersion element and the bandwidth of shaped spectrum in this scheme. In the experiment, non-return-to-zero(NRZ) signal with bit rate of 29.41 Gbit/s and 1/2 duty ratio return-to-zero(RZ) signal with bit rate of 13.51 Gbit/s are obtained. The maximum bit rate of modulation format signal is also analyzed.展开更多
Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequen...Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequency modulation to amplitude modulation(FM-to-AM)conversion in high power laser facility is demonstrated.The Jones matrix is applied to analyze the relationship between optical characteristics of the filter and physical parameters(including amplitude ratio,phase delay,and susceptibility of the birefringence to temperature)of the polarization optical field.Both the transmission peak wavelength and extinction ratio of the spectral transmission are able to be changed simultaneously,hence,it shows more efficient FM-to-AM compensation ability.Besides,the transmission peak shift is about 18pm/°C with the PM-PCF configuration,which is about two orders of magnitude less than the normal polarization maintaining fiber(PMF)configuration.The demonstrated filter presents a practical application potential in large scale laser driven facility.展开更多
文摘Controlled thermonuclear reactors require consistent monitoring of plasma in the toroidal chamber.Better working conditions of such machines can be monitored by analyzing its radiations.Various wavelengths such as 656.3,486.1,464.7 nm are quite significant which are used for health monitoring of thermonuclear machines.The optical thinfilmfilters which work on construc-tive and destructive interference are the ideal choices.Thesefilters are multi-layered with a pair of high and low refractive index dielectric materials.Significantly high transmission index at the desired wavelength and relatively low transmission at the other wavelengths are desired.With this as the objective,it is necessary to design thefilter.Various optimization techniques are used for identifying the suitable design of thefilters.To choose the parameter combination that provides the most excellent performance,optimization of the design para-meters is entailed.The goal of this work is to improve the optical bandfilter using the Bald eagle search optimization(BES)method.The ideal design is determined by assessing several characteristics such as thickness,refractive index,Full-Width at Half-Maximum(FWHM),and the impact of choosing optical properties,which increases transmission potential.Initially,an alternate multi-layer stack with 28,30,and 32 layers is created by altering the thickness while keeping the dielectric substances high and low refractive indices constant.By adjusting the thickness of each layer,the BES algorithm achieves the best practical solution.The proposed method is implemented using MATLAB and the outcomes show the efficacy of the proposed technique.The transmittance,reflectance,and FWHM using the pro-posed BES are found to be 99.9356%,0.065%,and 1.2 nm respectively.
基金the National Natural Science Foundation of China(Grant Nos.61975102 and 11974226)the National Key Research and Development Program of China(Grant No.2017YFA0304502)+1 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi,China(Grant No.2019L0101)the Natural Science Foundation of Shanxi Province,China(Grant No.20210302123437).
文摘A narrow linewidth Faraday anomalous dispersion optical filter(FADOF)with reflection configuration is achieved for the first time based on the cesium(Cs)ground state 6S_(1/2) to the excited state 6P_(3/2) transition at 852 nm.Compared with the conventional FADOF with transmission configuration,reflection-type FADOF can greatly improve the transmittance of optical filter under the same experimental parameters,because it allows signal light to go and return through the atomic vapor cell.In our experiment,peak transmittance at Cs 6S_(1/2) F=4-6P_(3/2) transition is 81%for the reflection-type FADOF,and while 54%for the transmission-type FADOF when the temperature of Cs vapor cell and the axial magnetic field are 60℃and 19 G.The idea of this reflection-type FADOF design has the potential to be applied to the FADOF operating between two excited states to obtain higher transmittance.
基金supported by the National Natural Science Foundation of China (Grant No.52076064)the Taishan Scholars of Shandong Province (tsqn 201812105)+1 种基金China Scholarship Council (202106120157)CSC grant for LIANG Huaxu's scholarship of research visiting at Nanyang Technological University, Singapore。
文摘Selective absorptive nanofluid can pre-absorb certain sunlight wavelength that cannot be used by PV and transmits remaining sunlight to the surface of PV,which can decouple PV from the thermal receiver spatially.In order to improve the harvesting of electricity and high-temperature thermal nanofluid,it is important to design an optimal optical filter window(transmit sunlight with wavelengths of 732-1067 nm to the surface of the photovoltaic cell and absorb the remaining sunlight).However,designing optimal optical filter is facing following challenges:(1) inherently narrow selective absorptivity property of single nanoparticle;(2) simplified numerical calculation method calculating transmittance;(3) ignoring the shape of the nanoparticle.In this study,the idea of using multiple nanoparticles coupling effect to design an optical filter is proposed,which can superimpose the narrow absorption bandwidth of different nanoparticles to obtain a wide absorption bandwidth of the whole system.In addition,an improved transmission method considering light-matter interaction at air/vessel and liquid/vessel interfaces is adopted to compute the transmittance.The results calculated by improved transmission method are more accurate than widely used traditional Lambert-Beer law,which is verified by experimental test.Furthermore,the effect of nanoparticle shape on spectral transmittance is also investigated,which shows that spiny Ag can approximately extend absorbance from 400 nm to 600 nm compared to nanosphere silver.Finally,the results show that optical filter efficiency of nanofluids with multiple nanoparticles coupling(Ag,spiny Ag,ZnO,ITO) can reached up to 35%.
基金RAT and GR gratefully acknowledge the support of the Australian Solar Institute and the UNSW ECR funding scheme.TO gratefully acknowledges support from USA NSF grant CBET-1066705.
文摘Optical filters are essential in a wide range of applications,including optical communications,electronics,lighting,optical sensors and photography.This article presents recent work which indicates that optical filters can be created from specialized nanoparticle suspensions.Specifically,this article describes a theoretical optimization process for designing nanofluid-based filters for hybrid solar photovoltaic/thermal(PV/T)applications.This particular application is suitable because nanofluids can be utilized as both volumetric solar absorbers and flowing heat transfer mediums.The nanofluid filters described in this work compare favorably with conventional optical filters for five photovoltaic(PV)cell alternatives:InGaP,CdTe,InGaAs,Si,and Ge.This study demonstrates that nanofluids make efficient,compact and potentially low-cost,spectrally selective optical filters.
基金supported by the National Science Fund for Distinguished Young Scholars of China (grant no. 61225003)the National Natural Science Foundation of China (grant nos. 61101081, 60837004, and 61401036)the National Hi-Tech Research and Development (863) Program
文摘A 459 nm Faraday anomalous dispersion optical filter（FADOF） working at the side wings of the cesium6S1∕2→ 7P1∕2transition with weak oscillator strength is achieved. The transmittance of the higher side wing reaches 98% at a temperature of 179°C and magnetic field above 323 G. The experimental results coincide with the theoretical predictions in 1982 and 1995, which were not realized in experiments for over three decades. Due to its high transmittance, high accuracy, and narrow linewidth, the 459 nm FADOF can be applied in underwater optical communications, the building of active optical clocks, and laser frequency stabilization in active optical clocks.
基金supported by the National Natural ScienceFoundation of China(No. 90201011)Sichuan Application basedResearch and Development Project(No.2008JY0064)the Fund of Dr. Development of Chinese Education Ministry(No.20070613058).
文摘To increase the channel number in the optic filter, the multiple-phase-shift (MPS) technology is adoped based on the multiple-reflection-spectrum-envelopes-concatenation (MRSEC) model which has a broadband flatness. The reflection spectra of the MPS digital concatenated sample gratings are simulated with transfer matrix method, the results show that wave band of the reflection spectrum is widened and the channel number is multiplied. What’s more, the spectrum flatness is improved with the increasing of refraction index change. Moreover, to improve the extinction ratio and peak value when MPS is adopted in concatenated SFBG, an available designing method based on the cascaded unit is put forward and the optimized results are obtained.
基金National Natural Science Foundation of China(NSFC)(61275043,61605128,61307048)
文摘A narrowband tunable antireflection optical filter is proposed and numerically studied. The structure is a metasurface based on plasmonic nanoparticles on an electro-optic film in a three-layer configuration of metaldielectric-metal(MDM) in the visible near-infrared range. By tuning the voltage and thus tuning the refractive index of the dielectric Li Nb O_3, one can shift the wavelength of minimum reflection as desired. The parameters of gold nanoparticles and other elements used for the filter design and refractive index of the dielectric are obtained by the finite-element method(FEM). An analytical theory is presented to explain the FEM simulation results, and they agree well with each other. It is found that the frequency of the plasmonic resonance wave on the metasurface should be equal to that of the Fabry–Perot resonator formed by the MDM to have a good filtering property. Theoretical spectra obtained by FEM simulation show that the structure has extensive potential for the design of tunable narrow-band filters for modulators, displayers, and color extraction for imaging.
基金the National Key Research and Development Program of China(No.2016YFA0200103)the National Natural Science Foundation of China(Nos.61527814,51702225,51432002,61474109,51290272,51502007,11474274,51520105003,51672007)+3 种基金National Equipment Program of China(No.ZDYZ2015-1)Beijing Municipal Science Technology Planning Project(Nos.Z 161100002116020,Z161100002116032)Beijing Natural Science Foundation(No.4182063)and Natural Science Foundation of Jiangsu Province(No.BK 20170336).
文摘Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by prevailing methodologies is normally of polycrystalline nature with high nucleation density and limited domain size,which significantly handicaps its overall properties and device performances.Herein,we report an oxygen-assisted CVD strategy to allow the direct synthesis of 6-inch-scale graphene glass harvesting markedly increased graphene domain size(from 0.2 to 1.8μm).Significantly,as-produced graphene glass attains record high electrical conductivity(realizing a sheet resistance of 900Ω·sq^(-1)at a visible-light transmittance of 92%)amongst the state-of-the-art counterparts,readily serving as transparent electrodes for fabricating high-performance optical filter devices.This work might open a new avenue for the scalable production and application of emerging graphene glass materials with high quality and low cost.
文摘A novel double-channel drop filter of single photons with only a drop waveguide is proposed. In the structure, two microresonators with a qubit are used to connect the drop waveguide and the bus waveguide with a reflector. By tuning the system parameters, multiple wavelengths with high drop efficiencies in two output channels of the drop waveguide are obtained. As the reflector is independent on its exact location, and one drop waveguide with two drop channels saves the integrated space, this may suggest a potential filtering device which functions in photonic integrated circuits and dense wavelength division multiplexing communication.
文摘In this paper human face machine identification is experienced using optical correlation techniques in spatial frequency domain. This approach is tested on ORL dataset of faces which includes face images of 40 subjects, each in 10 different positions. The examined optical setup relies on optical correlation based on developing optical Vanderlugt filters and its basics are described in this article. With the limitation of face database of 40 persons, the recognition is examined successfully with nearly 100% of accuracy in matching the input images with their respective Vanderlugt synthesized filters. Software simulation is implemented by using MATLAB for face identification.
文摘A new four-channel demultiplexer of single photons is proposed, in which four microresonators are utilized to link the four drop waveguides and the bus waveguide. By adjusting the system parameters, the crosstalk effect of the multiple channel frequencies is suppressed, and multiple peak frequencies with high drop efficiencies in these output ports are achieved. As the 2 × 2 model is scalable, the proposed structure can provide potential applications in designing scalable optical devices.
文摘One-dimensional photonic crystals (1D PhCs) have a unique ability to control the propagation of light waves, however certain classes of 1D oxides remain relatively unexplored for use as PhCs. Specifically, there has not been a comparative study of the three different 1D PhC structures to compare the influence of layer thickness, number, and refractive index on the ability of the PhCs to control light transmission. Herein, we use the transfer matrix method (TMM) to theoretically examine the transmission of 1D PhCs composed of layers of TiO<sub>2</sub>/SiO<sub>2</sub>, TiO<sub>2</sub>/SnO<sub>2</sub>, SiO<sub>2</sub>/SnO<sub>2</sub>, and combinations of the three with various top and bottom layer thicknesses to cover a substantial region of the electromagnetic spectrum (UV to NIR). With increasing layer numbers for TiO<sub>2</sub>/SiO<sub>2</sub> and SiO<sub>2</sub>/SnO<sub>2</sub>, the edges became sharper and wider and the photonic bandgap width increased. Moreover, we demonstrated that PhCs with significantly thick TiO<sub>2</sub>/SiO<sub>2</sub> layers had a high transmittance for a wide bandgap, allowing for wide-band optical filter applications. These different PhC architectures could enable a variety of applications, depending on the properties needed.
基金supported by the National Natural Science Foundation of China(Grant No.61971459)the Fund from Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.JCYJ2019080909-5009521)+2 种基金the Innovation Team Program of Hubei Province,China(Grant No.2019CFA004)the Innovation Fund of Wuhan National Laboratory for Optoelectronics&Optical Valley Laboratory(WNLO)2022 Shenzhen Central Leading Local Science and Technology Development Special Funding Program Virtual University Park Laboratory Project.
文摘Transparent electro-optic(EO)ceramics of La-doped 0.75Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.25PbTiO_(3)(0.75PMN-0.25PT)were prepared successfully.High transparency of 69%in the near-infrared(IR)wavelength(1550 nm)was achieved at 2 mo1%La doping,meanwhile it shows an extremely high quadratic EO coeficient of 45.4×10^(-16)m^(2)·V^(-2),which s indispensable for applications in EO devices.The distribution of a polar nanodomain structure of the samples experiences disorder-order-disorder evolution in a La doping range.It is found that a parallelly-stacked polar nanodomain structure with an easier and faster polarization switching in the 2 mol%La-doped sample suggests that an ordering distribution of polar nanoregions would be critical to inducing large EO effect,transparency,and piezoelectric response.A triple-cavity tunable optical filter(TOF)with a single transmission peak and a tuning voltage below 30 V in a tuning range of 190-197 THz was designed based on our ceramics.The work is believed to bridge the relationship among doping-engineering,EO properties,and polarization behavior,which would guide the further optimization of transparent EO ceramics.
文摘GFFs with less than 0.4 dB peak-to-peak error functions are routinely fabricated using commercially available coating machines by utilizing the natural error compensation mechanism of wavelength variable turning point optical monitoring method.
文摘A wavelength filter with simple structure using multimode waveguide is proposed. The device uses mode conversion by a grating structure fabricated simultaneously with the multimode waveguide.
文摘Optical comb filters based on multi-port fused fiber couplers are proposed and numerically analyzed, 3-arm MZI composed by 1×7 fiber splitter and 3×3 fiber coupler, and 2-stage cascaded FIR type MZI interleave filter.
文摘A novel acousto-optic tunable filter (AOTF) using a hollow optical fiber (HOF) is proposed. Its broadband rejection over 100nm was observed and high polarization dependence as a polarization switch is discussed.
基金supported by the National Natural Science Foundation of China(No.61377075)the Tianjin Natural Science Foundation(No.17JCYBJC16600)
文摘An optical modulation format generation scheme based on spectral filtering and frequency-to-time mapping is experimentally demonstrated. Many modulation formats with continuously adjustable duty radio and bit rate can be formed by changing the dispersion of dispersion element and the bandwidth of shaped spectrum in this scheme. In the experiment, non-return-to-zero(NRZ) signal with bit rate of 29.41 Gbit/s and 1/2 duty ratio return-to-zero(RZ) signal with bit rate of 13.51 Gbit/s are obtained. The maximum bit rate of modulation format signal is also analyzed.
基金This work was supported by the Science and Technology Major Project of Guangxi(Grant No.AA18118032)Laser Fusion Research Center Funds for Young Talents(Grant No.RCFCZ3-2019-7).
文摘Utilizing polarization maintaining photonic crystal fiber(PM-PCF)with the low temperature coefficient of birefringence,a two-dimensional tunable and temperature-insensitive Lyot filter aiming to compensate the frequency modulation to amplitude modulation(FM-to-AM)conversion in high power laser facility is demonstrated.The Jones matrix is applied to analyze the relationship between optical characteristics of the filter and physical parameters(including amplitude ratio,phase delay,and susceptibility of the birefringence to temperature)of the polarization optical field.Both the transmission peak wavelength and extinction ratio of the spectral transmission are able to be changed simultaneously,hence,it shows more efficient FM-to-AM compensation ability.Besides,the transmission peak shift is about 18pm/°C with the PM-PCF configuration,which is about two orders of magnitude less than the normal polarization maintaining fiber(PMF)configuration.The demonstrated filter presents a practical application potential in large scale laser driven facility.
