A novel into-plane rotating rnicromirror actuated by a hybrid electrostatic driving structure is presented. The hybrid driving structure is made up of a planar plate drive and a vertical comb drive. The device is fabr...A novel into-plane rotating rnicromirror actuated by a hybrid electrostatic driving structure is presented. The hybrid driving structure is made up of a planar plate drive and a vertical comb drive. The device is fabricated in SOI substrate by using a bulk-and-surface mixed silicon micromachining process. As demonstrated by experiment, the novel driving structure can actuate the mirror to achieve large-range continuous rotation as well as spontaneous 90°rotation induced by the pull-in effect. The continuous rotating range of the micromirror is increased to about 46° at an increased yielding voltage. The measured yielding voltages of the mirrors with torsional springs of 1 and 0.5μm in thickness are 390 - 410V and 140 - 160V, respectively. The optical insertion loss has also been measured to be --1.98dB when the mirror serves as an optical switch.展开更多
In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the...In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the equation gov- erning the static behavior of nano/micromirror under electro- static and vdW forces. Then, the stability of static equilib- rium points is analyzed using the energy method. It is found that when there exist two equilibrium points, the smaller one is stable and the larger one is unstable. The effects of dif- ferent design parameters on the mirror＇s pull-in angle and pull-in voltage are studied and it is found that vdW force can considerably reduce the stability limit of the mirror. At the end, the nonlinear equilibrium equation is solved numer- ically and analytically using homotopy perturbation method （HPM）. It is observed that a sixth order perturbation approx- imation can precisely model the mirror＇s behavior. The re- suits of this paper can be used for stable operation design and safe fabrication of torsional nano/micro actuators.展开更多
Structured illumination microscopy(SIM)is a promising super-resolution technique for imaging subcellular structures and dynamics due to its compatibility with most commonly usedffuorescent labeling methods.Structured ...Structured illumination microscopy(SIM)is a promising super-resolution technique for imaging subcellular structures and dynamics due to its compatibility with most commonly usedffuorescent labeling methods.Structured illumination can be obtained by either laser interference or projection of fringe patterns.Here,we proposed a fringe projector composed of a compact multiwavelength LEDs module and a digital micromirror device(DMD)which can be directly attached to most commercial invertedffuorescent microscopes and update it into a SIM system.The effects of the period and duty cycle of fringe patterns on the modulation depth of the structured lightfield were studied.With the optimized fringe pattern,1:6×resolution improvement could be obtained with high-end oil objectives.Multicolor imaging and dynamics of subcellular organelles in live cells were also demonstrated.Our method provides a low-cost solution for SIM setup to expand its wide range of applications to most research labs in thefield of life science and medicine.展开更多
We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investig...We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.展开更多
Numerical solutions could not perform rapid system-level simulation of the behavior of micro-electro-mechanical systems（MEMS） and analytic solutions for the describing partial differential equations are only availab...Numerical solutions could not perform rapid system-level simulation of the behavior of micro-electro-mechanical systems（MEMS） and analytic solutions for the describing partial differential equations are only available for simple geometries.Model order reduction（MOR） can extract approximate low-order model from the original large scale system.Conventional model order reduction algorithm is based on first-order system model,however,most structure mechanical MEMS systems are naturally second-order in time.For the purpose of solving the above problem,a direct second-order system model order reduction approach based on Krylov subspace projection for the coupled dynamic study of electrostatic torsional micromirrors is presented.The block Arnoldi process is applied to create the orthonormal vectors to construct the projection matrix,which enables the extraction of the low order model from the discretized system assembled through finite element analysis.The transfer functions of the reduced order model and the original model are expanded to demonstrate the moment-matching property of the second-order model reduction algorithm.The torsion and bending effect are included in the finite element model,and the squeeze film damping effect is considered as well.An empirical method considering relative error convergence is adopted to obtain the optimal choice of the order for the reduced model.A comparison research between the full model and the reduced model is carried out.The modeling accuracy and computation efficiency of the presented second-order model reduction method are confirmed by the comparison research results.The research provides references for MOR of MEMS.展开更多
With surface- and bulk-micromachining, an 8 × 8 mirrors array is designed, fabricated and tested, which is based on electro-thermal actuators and can be addressed individually. The micromirror is square shaped, 4...With surface- and bulk-micromachining, an 8 × 8 mirrors array is designed, fabricated and tested, which is based on electro-thermal actuators and can be addressed individually. The micromirror is square shaped, 4-corner-actuated. Its dimension is 200 μm × 200 μm. The substrate below it is caved away to ensure a tilt at an angle as large as possible. To protect the etch-sensitive features on the front side of the wafer undamaged during wet deep silicon etch on the backside, the wax protective coating process is used. Mirror actuated by powering an alternative pair of heaters will tilt in 2-DOF. If its 4 cantilevers/heaters are powered synchronously, it will move in a piston mode. The effective arrays are more than 80% out of the three finished wafers. When the ramp voltage frequency applied to a pair of neighboring cantilevers is 5 Hz at 10 V, the average tilting angle can be ± 8°.展开更多
Torsional micromirror devices have been widely used in micro displays,RF switches,optical communications,and optical coherence tomography systems.In order to study the stability of electrostatically driven torsional m...Torsional micromirror devices have been widely used in micro displays,RF switches,optical communications,and optical coherence tomography systems.In order to study the stability of electrostatically driven torsional micromirror system with double bottom plates and two voltage sources,a dimensionless,two degrees of freedom(2-DoF)dynamic model was constructed.Governed by the dimensionless phase space model equation,the pull-in and bifurcation phenomena were analyzed using the Hamiltonian method and numerical simulation.In particular,the influence of the damping coefficient and the torsion-bending coupling effect on the phase trajectory was investigated.Furthermore,the conditions that can lead to pull-in were numerically determined for saddle-node,pitchfork and Hopf bifurcations in the framework of 2-DoF system.Result showed that the dynamic pull-in voltage as predicted by the proposed 2-DoF system model is considerably lower than that by the one degree of freedom(1-DoF)system model.It was also confirmed that the pull-in voltage varies with the damping coefficient and/or the ratio of the two voltages applied to the bottom plates of the micromirror.The modelling method and stability analysis presented in this paper shall provide valuable insight to the design and control of electrostatically actuated micromirror systems.展开更多
Electrostatic torsional micromirrors are widely applied in the fields·of micro-optical switches,optical attenuators,optical scanners,and optical displays.In previous lectures,most of the micromirrors were twisted...Electrostatic torsional micromirrors are widely applied in the fields·of micro-optical switches,optical attenuators,optical scanners,and optical displays.In previous lectures,most of the micromirrors were twisted along the urtiaxial or biaxial direction,which limited the range of light reflection.In this·paper,a quasicrystal torsional micromirror that can be deflected in any direction is designed and the dynamic model of the electrostatically driven micromirror is established.The static and dynamic phenomena and pull-in characteristics are analyzed through the numerical solution of the strain gradient theory.The results of three kinds of mirror deflection directions are compared and analyzed.The results show the significant differences in the torsion models with different deflection axis directions.When the deflection angle along the oblique axis reaches 45°,the instability voltage is the smallest.The pull-in instability voltage increases with the increment ofphonon-phason coupling elastic modulus and phason elastic modulus.The perrriittivity of quasicrystal,the strain gradient parameter,and the air damping influence the torsion of the micromirror dynaniic system.A larger pull-in instability voltage generates with the decrease of surface distributed forces.展开更多
In this paper,we present a twisting control scheme with proportional-integral-derivative(PID)sliding surface for a two-axis electrostatic torsional micromirror,and the utilization of the proposed scheme in a laser sca...In this paper,we present a twisting control scheme with proportional-integral-derivative(PID)sliding surface for a two-axis electrostatic torsional micromirror,and the utilization of the proposed scheme in a laser scanning system.The experimental results of set-point regulation verify that the proposed scheme provides enhanced transient response and positioning performance as compared to traditional sliding mode control.To evaluate the tracking performance of the closed-loop system,triangular waves with different frequencies are used as desired traces.With the proposed scheme the experimental results verified that the closed-loop controlled micromirror follows the given triangular trajectories precisely.A micromirror-based laser scanning system is developed to obtain images.When compared with open-loop control,the experimental results demonstrated that the proposed scheme is able to reduce the distortion of the raster scan,and improve the imaging performance in the presence of cross-coupling effect.展开更多
An ultrafast spectrum programmable femtosecond laser may enhance the performance of a wide variety of scientific applications,e.g.,multi-photon imaging.In this paper,we report a digital micromirror device(DMD)-based u...An ultrafast spectrum programmable femtosecond laser may enhance the performance of a wide variety of scientific applications,e.g.,multi-photon imaging.In this paper,we report a digital micromirror device(DMD)-based ultrafast pulse shaper,i.e.,DUPS,for femtosecond laser arbitrary amplitude shaping-the first time a programmable binary device reported to shape the amplitudes of ultrafast pulses spectrum at up to 32 kHz rate over a broad wavelength range.The DUPS is highly effcient,compact,and low cost based on the use of a DMD in combination with a transmission grating.Spatial and temporal dispersion introduced by the DUPS is compensated by a quasi-4-f setup and a grating pair,respectively.Femtosecond pulses with arbitrary spectrum shapes,including rectangular,sawtooth,triangular,double-pulse,and exponential profile,have been demonstrated in our experiments.A feedback operation process is implemented in the DUPS to ensure a robust and repeatable shaping process.The total effciency of the DUPS for amplitude shaping is measured to be 27%.展开更多
Torsion micromirror is a key structure of optical devices in micro-electro-mechanical system(MEMS), such as MEMS optical switches, MEMS variable optical attenuator, MEMS scanning micromirror array and so on. A silicon...Torsion micromirror is a key structure of optical devices in micro-electro-mechanical system(MEMS), such as MEMS optical switches, MEMS variable optical attenuator, MEMS scanning micromirror array and so on. A silicon-based NiCrAu MEMS torsion micromirror is theoretically analyzed. It is shown that in order to have 15° rotation, the driven voltage should be about 20V and the thickness of the supporting beam must be controlled in the range of submicron orders of magnitude. This very thin beam makes the structure more unstable and unreliable, and also makes the fabrication more complicated. Based on parallel back-electrode analysis and testing, a tilted back-electrode has been designed to replace the parallel back-electrode in order to decrease the driven voltage and difficulty of fabricating processing. By theoretical analysis and simulation, a conclusion can be drown that the thickness can be improved from submicron to micron by using tilted back-electrode when using the same driven voltage. Tilted back-electrode is very effective to improve the stability and reliability of the micromirror structure.展开更多
Nonlinear spring characteristics of the tense torsion bar in the gap-closing type electrostatic micromirror are examined. The macro model is introduced for the experimental study. The tension applied in the torsion ba...Nonlinear spring characteristics of the tense torsion bar in the gap-closing type electrostatic micromirror are examined. The macro model is introduced for the experimental study. The tension applied in the torsion bar is well controlled using the electromagnetic attraction. This controllability is suited for clearing the nonlinear nature. The tension is confirmed to have the effect to widen the controllable angle range of the mirror suppressing the pull-in. The pull-in angle is observed to increases to about 74% of the mechanical limit angle at the tension of 0,96 N. This is significantly larger than 44% of the case with the linear spring. The larger resonant frequency is maintained. The hardening of the spring can keep the balance with the electrostatic force over the limit of the linear spring. The observed features are explained reasonably with the combination of twisting and bending displacements of the torsion bar.展开更多
A tip-tilt-piston 3×3 electrothermal micromirror array(MMA)integrated with temperature field-based position sensors is designed and fabricated in this work.The size of the individual octagonal mirror plates is as...A tip-tilt-piston 3×3 electrothermal micromirror array(MMA)integrated with temperature field-based position sensors is designed and fabricated in this work.The size of the individual octagonal mirror plates is as large as 1.6 mm×1.6 mm.Thermal isolation structures are embedded to reduce the thermal coupling among the micromirror units.Results show that each micromirror unit has a piston scan range of 218μm and a tip-tilt optical scan angle of 21°at only 5 Vdc.The micromirrors also exhibit good dynamic performance with a rise time of 51.2 ms and a fall time of 53.6 ms.Moreover,the on-chip position sensors are proven to be capable for covering the full-range movement of the mirror plate,with the measured sensitivities of 1.5 mV/μm and 8.8 mV/°in piston sensing and tip-tilt sensing,respectively.Furthermore,the thermal crosstalk in an operating MMA has been experimentally studied.The measured results are promising thanks to the embedded thermal isolation structures.展开更多
文摘A novel into-plane rotating rnicromirror actuated by a hybrid electrostatic driving structure is presented. The hybrid driving structure is made up of a planar plate drive and a vertical comb drive. The device is fabricated in SOI substrate by using a bulk-and-surface mixed silicon micromachining process. As demonstrated by experiment, the novel driving structure can actuate the mirror to achieve large-range continuous rotation as well as spontaneous 90°rotation induced by the pull-in effect. The continuous rotating range of the micromirror is increased to about 46° at an increased yielding voltage. The measured yielding voltages of the mirrors with torsional springs of 1 and 0.5μm in thickness are 390 - 410V and 140 - 160V, respectively. The optical insertion loss has also been measured to be --1.98dB when the mirror serves as an optical switch.
文摘In this paper, the effect of van der Waals （vdW） force on the pull-in behavior of electrostatically actuated nano/micromirrors is investigated. First, the minimum po- tential energy principle is utilized to find the equation gov- erning the static behavior of nano/micromirror under electro- static and vdW forces. Then, the stability of static equilib- rium points is analyzed using the energy method. It is found that when there exist two equilibrium points, the smaller one is stable and the larger one is unstable. The effects of dif- ferent design parameters on the mirror＇s pull-in angle and pull-in voltage are studied and it is found that vdW force can considerably reduce the stability limit of the mirror. At the end, the nonlinear equilibrium equation is solved numer- ically and analytically using homotopy perturbation method （HPM）. It is observed that a sixth order perturbation approx- imation can precisely model the mirror＇s behavior. The re- suits of this paper can be used for stable operation design and safe fabrication of torsional nano/micro actuators.
基金The study was funded by the National Key Technologies R&D Program of China(2018YFC0114800 and 2017YFC0109900)the Natural Science Foundation of China(NSFC)(61405238)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20141206)the Key Technologies R&D Program of Jiangsu Province(BE2018666).
文摘Structured illumination microscopy(SIM)is a promising super-resolution technique for imaging subcellular structures and dynamics due to its compatibility with most commonly usedffuorescent labeling methods.Structured illumination can be obtained by either laser interference or projection of fringe patterns.Here,we proposed a fringe projector composed of a compact multiwavelength LEDs module and a digital micromirror device(DMD)which can be directly attached to most commercial invertedffuorescent microscopes and update it into a SIM system.The effects of the period and duty cycle of fringe patterns on the modulation depth of the structured lightfield were studied.With the optimized fringe pattern,1:6×resolution improvement could be obtained with high-end oil objectives.Multicolor imaging and dynamics of subcellular organelles in live cells were also demonstrated.Our method provides a low-cost solution for SIM setup to expand its wide range of applications to most research labs in thefield of life science and medicine.
基金Supported by the Natural Science Foundation of Beijing under Grant Nos 2162033 and 7182091the National Natural Science Foundation of China under Grant No 21627813
文摘We present a digital micromirror device（DMD） based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.
基金supported by National Natural Science Foundation of China (Grant No. 50775201)National Science & Technology Major Project of China (Grant No. 2009ZX04014-031)PhD Programs Foundation of Ministry of Education of China (Grant No. 200803350031)
文摘Numerical solutions could not perform rapid system-level simulation of the behavior of micro-electro-mechanical systems（MEMS） and analytic solutions for the describing partial differential equations are only available for simple geometries.Model order reduction（MOR） can extract approximate low-order model from the original large scale system.Conventional model order reduction algorithm is based on first-order system model,however,most structure mechanical MEMS systems are naturally second-order in time.For the purpose of solving the above problem,a direct second-order system model order reduction approach based on Krylov subspace projection for the coupled dynamic study of electrostatic torsional micromirrors is presented.The block Arnoldi process is applied to create the orthonormal vectors to construct the projection matrix,which enables the extraction of the low order model from the discretized system assembled through finite element analysis.The transfer functions of the reduced order model and the original model are expanded to demonstrate the moment-matching property of the second-order model reduction algorithm.The torsion and bending effect are included in the finite element model,and the squeeze film damping effect is considered as well.An empirical method considering relative error convergence is adopted to obtain the optimal choice of the order for the reduced model.A comparison research between the full model and the reduced model is carried out.The modeling accuracy and computation efficiency of the presented second-order model reduction method are confirmed by the comparison research results.The research provides references for MOR of MEMS.
文摘With surface- and bulk-micromachining, an 8 × 8 mirrors array is designed, fabricated and tested, which is based on electro-thermal actuators and can be addressed individually. The micromirror is square shaped, 4-corner-actuated. Its dimension is 200 μm × 200 μm. The substrate below it is caved away to ensure a tilt at an angle as large as possible. To protect the etch-sensitive features on the front side of the wafer undamaged during wet deep silicon etch on the backside, the wax protective coating process is used. Mirror actuated by powering an alternative pair of heaters will tilt in 2-DOF. If its 4 cantilevers/heaters are powered synchronously, it will move in a piston mode. The effective arrays are more than 80% out of the three finished wafers. When the ramp voltage frequency applied to a pair of neighboring cantilevers is 5 Hz at 10 V, the average tilting angle can be ± 8°.
基金This work is supported by the National Natural Science Foundation of China(Project 61368004)the Fund of National High-level Overseas Talent Returning([2011]481)a scholarship from China Scholarship Council(No.201703000001).
文摘Torsional micromirror devices have been widely used in micro displays,RF switches,optical communications,and optical coherence tomography systems.In order to study the stability of electrostatically driven torsional micromirror system with double bottom plates and two voltage sources,a dimensionless,two degrees of freedom(2-DoF)dynamic model was constructed.Governed by the dimensionless phase space model equation,the pull-in and bifurcation phenomena were analyzed using the Hamiltonian method and numerical simulation.In particular,the influence of the damping coefficient and the torsion-bending coupling effect on the phase trajectory was investigated.Furthermore,the conditions that can lead to pull-in were numerically determined for saddle-node,pitchfork and Hopf bifurcations in the framework of 2-DoF system.Result showed that the dynamic pull-in voltage as predicted by the proposed 2-DoF system model is considerably lower than that by the one degree of freedom(1-DoF)system model.It was also confirmed that the pull-in voltage varies with the damping coefficient and/or the ratio of the two voltages applied to the bottom plates of the micromirror.The modelling method and stability analysis presented in this paper shall provide valuable insight to the design and control of electrostatically actuated micromirror systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.11572191,51701117,and 51779139).
文摘Electrostatic torsional micromirrors are widely applied in the fields·of micro-optical switches,optical attenuators,optical scanners,and optical displays.In previous lectures,most of the micromirrors were twisted along the urtiaxial or biaxial direction,which limited the range of light reflection.In this·paper,a quasicrystal torsional micromirror that can be deflected in any direction is designed and the dynamic model of the electrostatically driven micromirror is established.The static and dynamic phenomena and pull-in characteristics are analyzed through the numerical solution of the strain gradient theory.The results of three kinds of mirror deflection directions are compared and analyzed.The results show the significant differences in the torsion models with different deflection axis directions.When the deflection angle along the oblique axis reaches 45°,the instability voltage is the smallest.The pull-in instability voltage increases with the increment ofphonon-phason coupling elastic modulus and phason elastic modulus.The perrriittivity of quasicrystal,the strain gradient parameter,and the air damping influence the torsion of the micromirror dynaniic system.A larger pull-in instability voltage generates with the decrease of surface distributed forces.
基金supported by the National Natural Science Foundation of China(61374036,61703142,U1504615)the Natural Science and Engineering Research Council of Canadathe Scientific Research Key Foundation of Higher Education Institutions of Henan Province(16A413001)
文摘In this paper,we present a twisting control scheme with proportional-integral-derivative(PID)sliding surface for a two-axis electrostatic torsional micromirror,and the utilization of the proposed scheme in a laser scanning system.The experimental results of set-point regulation verify that the proposed scheme provides enhanced transient response and positioning performance as compared to traditional sliding mode control.To evaluate the tracking performance of the closed-loop system,triangular waves with different frequencies are used as desired traces.With the proposed scheme the experimental results verified that the closed-loop controlled micromirror follows the given triangular trajectories precisely.A micromirror-based laser scanning system is developed to obtain images.When compared with open-loop control,the experimental results demonstrated that the proposed scheme is able to reduce the distortion of the raster scan,and improve the imaging performance in the presence of cross-coupling effect.
基金This work is partially supported by the HKSAR Innovation and Technology Commission(ITC)Innovation and Technology Fund(ITF),ITS/179/16FP,as well as the HKSAR Research Grants Council,General Research Fund,Project No.14202815.
文摘An ultrafast spectrum programmable femtosecond laser may enhance the performance of a wide variety of scientific applications,e.g.,multi-photon imaging.In this paper,we report a digital micromirror device(DMD)-based ultrafast pulse shaper,i.e.,DUPS,for femtosecond laser arbitrary amplitude shaping-the first time a programmable binary device reported to shape the amplitudes of ultrafast pulses spectrum at up to 32 kHz rate over a broad wavelength range.The DUPS is highly effcient,compact,and low cost based on the use of a DMD in combination with a transmission grating.Spatial and temporal dispersion introduced by the DUPS is compensated by a quasi-4-f setup and a grating pair,respectively.Femtosecond pulses with arbitrary spectrum shapes,including rectangular,sawtooth,triangular,double-pulse,and exponential profile,have been demonstrated in our experiments.A feedback operation process is implemented in the DUPS to ensure a robust and repeatable shaping process.The total effciency of the DUPS for amplitude shaping is measured to be 27%.
基金Scientific Research Foundation(2003-52) and Youth Foundation(A2003-06) from Chongqing University ofPosts & Telecom
文摘Torsion micromirror is a key structure of optical devices in micro-electro-mechanical system(MEMS), such as MEMS optical switches, MEMS variable optical attenuator, MEMS scanning micromirror array and so on. A silicon-based NiCrAu MEMS torsion micromirror is theoretically analyzed. It is shown that in order to have 15° rotation, the driven voltage should be about 20V and the thickness of the supporting beam must be controlled in the range of submicron orders of magnitude. This very thin beam makes the structure more unstable and unreliable, and also makes the fabrication more complicated. Based on parallel back-electrode analysis and testing, a tilted back-electrode has been designed to replace the parallel back-electrode in order to decrease the driven voltage and difficulty of fabricating processing. By theoretical analysis and simulation, a conclusion can be drown that the thickness can be improved from submicron to micron by using tilted back-electrode when using the same driven voltage. Tilted back-electrode is very effective to improve the stability and reliability of the micromirror structure.
文摘Nonlinear spring characteristics of the tense torsion bar in the gap-closing type electrostatic micromirror are examined. The macro model is introduced for the experimental study. The tension applied in the torsion bar is well controlled using the electromagnetic attraction. This controllability is suited for clearing the nonlinear nature. The tension is confirmed to have the effect to widen the controllable angle range of the mirror suppressing the pull-in. The pull-in angle is observed to increases to about 74% of the mechanical limit angle at the tension of 0,96 N. This is significantly larger than 44% of the case with the linear spring. The larger resonant frequency is maintained. The hardening of the spring can keep the balance with the electrostatic force over the limit of the linear spring. The observed features are explained reasonably with the combination of twisting and bending displacements of the torsion bar.
基金funded in part by National Natural Science Foundation of China under Grants 62350710218,92373105 and 62074015National Key Research and Development Program of China(2023YFB3507300).
文摘A tip-tilt-piston 3×3 electrothermal micromirror array(MMA)integrated with temperature field-based position sensors is designed and fabricated in this work.The size of the individual octagonal mirror plates is as large as 1.6 mm×1.6 mm.Thermal isolation structures are embedded to reduce the thermal coupling among the micromirror units.Results show that each micromirror unit has a piston scan range of 218μm and a tip-tilt optical scan angle of 21°at only 5 Vdc.The micromirrors also exhibit good dynamic performance with a rise time of 51.2 ms and a fall time of 53.6 ms.Moreover,the on-chip position sensors are proven to be capable for covering the full-range movement of the mirror plate,with the measured sensitivities of 1.5 mV/μm and 8.8 mV/°in piston sensing and tip-tilt sensing,respectively.Furthermore,the thermal crosstalk in an operating MMA has been experimentally studied.The measured results are promising thanks to the embedded thermal isolation structures.
