DWDM technology is developing rapidly. Thin film narrow bandpass filter plays an important role in this field. This article presents some achievements in developing the DWDM narrow bandpass filters and also describes ...DWDM technology is developing rapidly. Thin film narrow bandpass filter plays an important role in this field. This article presents some achievements in developing the DWDM narrow bandpass filters and also describes the results achieved by us.展开更多
We propose and analyze a submicron stub-assisted ultrafast all-optical plasmonic switch based on nonlinear MIM waveguide. It is constructed by two silicon stub filters sandwiched by silver cladding. The signal wavelen...We propose and analyze a submicron stub-assisted ultrafast all-optical plasmonic switch based on nonlinear MIM waveguide. It is constructed by two silicon stub filters sandwiched by silver cladding. The signal wavelength is assumed to be 1550 nm. The simulation results show a ?14.66 dB extinction ratio. Downscaling the silicon waveguide in MIM structure leads to enhancement of the effective Kerr nonlinearity due to tight mode confinement. Also, using O+ ions implanted into silicon, the switching time less than 10 ps and a delay time less than 8 fs are achieved. The overall length of the switch is 550 nm.展开更多
High performance optical coating requires excellent uniformity of thin-film.Keeping the surface of evaporation material flat is propitious for the stability of vapor plume,and can improve the uniformity of thin-film.B...High performance optical coating requires excellent uniformity of thin-film.Keeping the surface of evaporation material flat is propitious for the stability of vapor plume,and can improve the uniformity of thin-film.Based on the principle of electron beam spot sweep,a pattern controller in domestic coater is designed.For the purpose of even evaporation during auto-sweep,the influence of the depth of material surface in the crucible on the evaporation characteristic is considered.Pre-melting and evaporation experiments are performed on melting material（Ti3O5）,subliming material（SiO2）,and semi-melting, semi-subliming material（HfO2）.The sweeping experimental results show that using the designed sweep controller can make good performance on evaporation and pre-melting for the above materials.展开更多
Utilizing a high-Q microdisk resonator （MDR） on a single silicon-on-insulator （SOI） chip, a compact microwave photonic filter （MPF） with a continuously tunable central frequency is proposed and experimentally de...Utilizing a high-Q microdisk resonator （MDR） on a single silicon-on-insulator （SOI） chip, a compact microwave photonic filter （MPF） with a continuously tunable central frequency is proposed and experimentally demonstrated. Assisted by the optical single side-band （OSSB） modulation, the optical frequency response of the MDR is mapped to the microwave frequency response to form an MPF with a continuously tunable central frequency and a narrow 3-dB bandwidth. In the experiment, using an MDR with a compact size of 20×20 μm^2 and a high Q factor of 1.07×10^5, we obtain a compact MPF with a high rejection ratio of about 40 dB, a 3-dB bandwidth of about 2 GHz, and a frequency tuning range larger than 12 GHz. Our approach may allow the implementation of very compact, low-cost, low-consumption, and integrated notch MPF in a silicon chip.展开更多
We designed a reconfigurable dual-interferometer coupled silicon nitride microring resonator.By tuning the integrated heater on interferometer's arms,the"critical coupling"bandwidth of resonant mode is c...We designed a reconfigurable dual-interferometer coupled silicon nitride microring resonator.By tuning the integrated heater on interferometer's arms,the"critical coupling"bandwidth of resonant mode is continuously adjustable whose quality factor varies from 7.9×10^(4) to 1.9×10^(5) with the extinction ratio keeping higher than 25 dB.Also a variety of coupling spanning from"under-coupling"to"over-coupling"were achieved,showing the ability to tune the quality factor from 6.0×10^(3) to 2.3×10^(5).Our design can provide an adjustable filtering method on silicon nitride photonic chip and contribute to optimize the nonlinear process for quantum photonics and all-optical signal processing.展开更多
The advent of the laser has placed stringent requirements on the fabrication, performance and quality of optical elements employed within systems for most practical applications. Their high power performance is genera...The advent of the laser has placed stringent requirements on the fabrication, performance and quality of optical elements employed within systems for most practical applications. Their high power performance is generally governed by three distinct steps, firstly the absorption of incident optical radiation (governed primarily by various absorption mechanisms);secondly, followed by a temperature increase and response governed primarily by thermal properties and finally the elements thermo-optical and thermomechanical response, e.g., distortion, stress birefringenous fracture, etc. All of which needs to be understood in the design as efficient, compact, reliable and useful for many applications high power systems, under a variety of operating conditions, pulsed and continuous wave, rep-rated or burst mode of varying duty cycles.展开更多
A method for fabrication of ultravi olet induced transmission (IT) filter by visible light control in an ordinary vacuum is presented. Manu facturing principles and techniques are disscussed. Measured spectral transmi...A method for fabrication of ultravi olet induced transmission (IT) filter by visible light control in an ordinary vacuum is presented. Manu facturing principles and techniques are disscussed. Measured spectral transmitta nce curves of making ultraviolet IT filter by this method are given.展开更多
Free-spectral-range(FSR)-free optical filters have always been a critical challenge for photonic integrated circuits.A high-performance FSR-free filter is highly desired for communication,spectroscopy,and sensing appl...Free-spectral-range(FSR)-free optical filters have always been a critical challenge for photonic integrated circuits.A high-performance FSR-free filter is highly desired for communication,spectroscopy,and sensing applications.Despite significant progress in integrated optical filters,the FSR-free filter with a tunable narrow-band,high out-of-band rejection,and large fabrication tolerance has rarely been demonstrated.In this paper,we propose an exact and robust design method for add-drop filters(ADFs)with an FSR-free operation capability,a sub-nanometer optical bandwidth,and a high out-of-band rejection(OBR)ratio.The achieved filter has a 3-dB bandwidth of<0.5 nm and an OBR ratio of 21.5 dB within a large waveband of 220 nm,which to the best of our knowledge,is the largest-FSR ADF demonstrated on a silicon photonic platform.The filter exhibits large tunability of 12.3 nm with a heating efficiency of 97 pm/mW and maintains the FSR-free feature in the whole tuning process.In addition,we fabri-cated a series of ADFs with different periods,which all showed reliable and excellent performances.展开更多
In this letter, we propose a voltage-controlled optical filter based on electrowetting. The device is made of a transparent cubic cell filled with two immiscible liquids having three indium tin oxide electrodes fabric...In this letter, we propose a voltage-controlled optical filter based on electrowetting. The device is made of a transparent cubic cell filled with two immiscible liquids having three indium tin oxide electrodes fabricated on the bottom substrate of the cell. A conductive droplet carrying a color filter is placed on the ITO electrode and the surrounding liquid is density-matched silicone oil. Under zero bias, the droplet is placed in the middle of tile substrate and white light passes through the filter and we can see red light on the screen. When a voltage is applied to the device, the filter moves with the liquid based on electrowetting effect, we can see the white light on the screen. Due to the movement of the liqnid, our device functions as an optical switcher. The switch trine of the device is -70 ms. The proposed device has a wide application in optical communication. electronic display, and optical switch.展开更多
文摘DWDM technology is developing rapidly. Thin film narrow bandpass filter plays an important role in this field. This article presents some achievements in developing the DWDM narrow bandpass filters and also describes the results achieved by us.
文摘We propose and analyze a submicron stub-assisted ultrafast all-optical plasmonic switch based on nonlinear MIM waveguide. It is constructed by two silicon stub filters sandwiched by silver cladding. The signal wavelength is assumed to be 1550 nm. The simulation results show a ?14.66 dB extinction ratio. Downscaling the silicon waveguide in MIM structure leads to enhancement of the effective Kerr nonlinearity due to tight mode confinement. Also, using O+ ions implanted into silicon, the switching time less than 10 ps and a delay time less than 8 fs are achieved. The overall length of the switch is 550 nm.
文摘High performance optical coating requires excellent uniformity of thin-film.Keeping the surface of evaporation material flat is propitious for the stability of vapor plume,and can improve the uniformity of thin-film.Based on the principle of electron beam spot sweep,a pattern controller in domestic coater is designed.For the purpose of even evaporation during auto-sweep,the influence of the depth of material surface in the crucible on the evaporation characteristic is considered.Pre-melting and evaporation experiments are performed on melting material（Ti3O5）,subliming material（SiO2）,and semi-melting, semi-subliming material（HfO2）.The sweeping experimental results show that using the designed sweep controller can make good performance on evaporation and pre-melting for the above materials.
基金supported by the National Basic Research Program of China(Grant No.2011CB301704)the Program for New Century Excellent Talents in Ministry of Education of China(Grant No.NCET-11-0168)+1 种基金the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No.201139)the National Natural Science Foundation of China(Grant Nos.60901006 and 11174096)
文摘Utilizing a high-Q microdisk resonator （MDR） on a single silicon-on-insulator （SOI） chip, a compact microwave photonic filter （MPF） with a continuously tunable central frequency is proposed and experimentally demonstrated. Assisted by the optical single side-band （OSSB） modulation, the optical frequency response of the MDR is mapped to the microwave frequency response to form an MPF with a continuously tunable central frequency and a narrow 3-dB bandwidth. In the experiment, using an MDR with a compact size of 20×20 μm^2 and a high Q factor of 1.07×10^5, we obtain a compact MPF with a high rejection ratio of about 40 dB, a 3-dB bandwidth of about 2 GHz, and a frequency tuning range larger than 12 GHz. Our approach may allow the implementation of very compact, low-cost, low-consumption, and integrated notch MPF in a silicon chip.
基金the National Key Research and Development Program of China(Grant Nos.2019YFA0308700and 2017YFA0303700)the National Natural Science Foundation of China(Grant Nos.11627810 and 11690031)the Open Funds from the State Key Laboratory of High Performance Computing of China(HPCL,National University of Defense Technology).
文摘We designed a reconfigurable dual-interferometer coupled silicon nitride microring resonator.By tuning the integrated heater on interferometer's arms,the"critical coupling"bandwidth of resonant mode is continuously adjustable whose quality factor varies from 7.9×10^(4) to 1.9×10^(5) with the extinction ratio keeping higher than 25 dB.Also a variety of coupling spanning from"under-coupling"to"over-coupling"were achieved,showing the ability to tune the quality factor from 6.0×10^(3) to 2.3×10^(5).Our design can provide an adjustable filtering method on silicon nitride photonic chip and contribute to optimize the nonlinear process for quantum photonics and all-optical signal processing.
文摘The advent of the laser has placed stringent requirements on the fabrication, performance and quality of optical elements employed within systems for most practical applications. Their high power performance is generally governed by three distinct steps, firstly the absorption of incident optical radiation (governed primarily by various absorption mechanisms);secondly, followed by a temperature increase and response governed primarily by thermal properties and finally the elements thermo-optical and thermomechanical response, e.g., distortion, stress birefringenous fracture, etc. All of which needs to be understood in the design as efficient, compact, reliable and useful for many applications high power systems, under a variety of operating conditions, pulsed and continuous wave, rep-rated or burst mode of varying duty cycles.
文摘A method for fabrication of ultravi olet induced transmission (IT) filter by visible light control in an ordinary vacuum is presented. Manu facturing principles and techniques are disscussed. Measured spectral transmitta nce curves of making ultraviolet IT filter by this method are given.
基金National Key Research and Development Program of China(2019YFB2203003)National Natural Science Foundation of China(62175202 and 91950204)+2 种基金Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2020R01005)the Open Research program of Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang ProvinceWestlake University(the start-up fund of Westlake University).
文摘Free-spectral-range(FSR)-free optical filters have always been a critical challenge for photonic integrated circuits.A high-performance FSR-free filter is highly desired for communication,spectroscopy,and sensing applications.Despite significant progress in integrated optical filters,the FSR-free filter with a tunable narrow-band,high out-of-band rejection,and large fabrication tolerance has rarely been demonstrated.In this paper,we propose an exact and robust design method for add-drop filters(ADFs)with an FSR-free operation capability,a sub-nanometer optical bandwidth,and a high out-of-band rejection(OBR)ratio.The achieved filter has a 3-dB bandwidth of<0.5 nm and an OBR ratio of 21.5 dB within a large waveband of 220 nm,which to the best of our knowledge,is the largest-FSR ADF demonstrated on a silicon photonic platform.The filter exhibits large tunability of 12.3 nm with a heating efficiency of 97 pm/mW and maintains the FSR-free feature in the whole tuning process.In addition,we fabri-cated a series of ADFs with different periods,which all showed reliable and excellent performances.
基金supported by the National Natural Science Foundation of China(Nos.61225022 and 61320106015)the National "973" Program of China(No.2013CB328802)+1 种基金the National "863" Program of China(No.2012AA011901)the Research Program of Sichuan Province,China(No.2013TD0002)
文摘In this letter, we propose a voltage-controlled optical filter based on electrowetting. The device is made of a transparent cubic cell filled with two immiscible liquids having three indium tin oxide electrodes fabricated on the bottom substrate of the cell. A conductive droplet carrying a color filter is placed on the ITO electrode and the surrounding liquid is density-matched silicone oil. Under zero bias, the droplet is placed in the middle of tile substrate and white light passes through the filter and we can see red light on the screen. When a voltage is applied to the device, the filter moves with the liquid based on electrowetting effect, we can see the white light on the screen. Due to the movement of the liqnid, our device functions as an optical switcher. The switch trine of the device is -70 ms. The proposed device has a wide application in optical communication. electronic display, and optical switch.
