Piezoelectric tip/tilt stages(PZT stages),which precisely and quickly control laser beam deflection,are widely used in laser communications.Most are driven by piezoelectric stack actuators(PSAs)and have high capacitan...Piezoelectric tip/tilt stages(PZT stages),which precisely and quickly control laser beam deflection,are widely used in laser communications.Most are driven by piezoelectric stack actuators(PSAs)and have high capacitance and power consumption.The negative voltage causes irreversible damage to PSAs.Therefore,negative voltage operation needs to be prohibited,which complicates manipulating the bidirectional deflection of the mirror.However,the aerospace field places higher requirements on power consumption and ease of operation,which makes the PZT stage require reduced power consumption and simple operation.This paper presents a high-performance bend-actuated PZT stage,which uses ceramic plates for driving,with a capacitance of only 26.4 nF/axis and a power of only 27 mW(at operating conditions of 1 mrad and 100 Hz).The sandwich structure allows for bi-directional voltage,which makes the operation easier.Two channels control two degrees of freedom(DOFs).A theoretical model suitable for bend-actuated structures is proposed.It is used to calculate the deflection angle and resonance frequency,and its validity is verified by finite element analysis.Experimental results show that it has a deflection angle of±2.97 mrad(x-axis),±3.24 mrad(y-axis)at 600 V p-p,an unloaded first-order resonance frequency of 1728 Hz,and a quasi-static hysteresis of only 7.5%,which is less than that of PSAs(>10%).With the constructed laser beam deflection system,a circular trajectory is realized,which has the potential for beam steering.展开更多
We present an experimental study on tilt-tip（TT） and phase-locking（PL） control in a coherent beam combination（CBC） system of adaptive fiber laser array.The TT control is performed using the adaptive fiber-optics...We present an experimental study on tilt-tip（TT） and phase-locking（PL） control in a coherent beam combination（CBC） system of adaptive fiber laser array.The TT control is performed using the adaptive fiber-optics collimator（AFOC）,and the PL control is realized by the phase modulator（PM）.Cascaded and simultaneous controls of TT and PL using stochastic parallel gradient descent（SPGD） algorithm are investigated in this paper.Two-fiber-laser-,four-fiber-laser-,and six-fiber-laser-arrays are employed to study the TT and PL control.In the cascaded control system,only one high-speed CMOS camera is used to collect beam data and a computer is used as the controller.In a simultaneous control system one high-speed CMOS camera and one photonic detector（PD） are employed,and a computer and a control circuit based on field programmable gate array（FPGA） are used as the controllers.Experimental results reveal that both cascaded and simultaneous controls of TT using AFOC and PL using PM in fiber laser array are feasible and effective.Cascaded control is more effective in static control situation and simultaneous control can be applied to the dynamic control system directly.The control signals of simultaneous PL and TT disturb each other obviously and TT and PL control may compete with each other,so the control effect is limited.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62227812,524B2053,52225501)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20240959)the Self-Planned Task of State Key Laboratory of Robotics and Systems(HIT)(Grant No.SKLRS202302C).
文摘Piezoelectric tip/tilt stages(PZT stages),which precisely and quickly control laser beam deflection,are widely used in laser communications.Most are driven by piezoelectric stack actuators(PSAs)and have high capacitance and power consumption.The negative voltage causes irreversible damage to PSAs.Therefore,negative voltage operation needs to be prohibited,which complicates manipulating the bidirectional deflection of the mirror.However,the aerospace field places higher requirements on power consumption and ease of operation,which makes the PZT stage require reduced power consumption and simple operation.This paper presents a high-performance bend-actuated PZT stage,which uses ceramic plates for driving,with a capacitance of only 26.4 nF/axis and a power of only 27 mW(at operating conditions of 1 mrad and 100 Hz).The sandwich structure allows for bi-directional voltage,which makes the operation easier.Two channels control two degrees of freedom(DOFs).A theoretical model suitable for bend-actuated structures is proposed.It is used to calculate the deflection angle and resonance frequency,and its validity is verified by finite element analysis.Experimental results show that it has a deflection angle of±2.97 mrad(x-axis),±3.24 mrad(y-axis)at 600 V p-p,an unloaded first-order resonance frequency of 1728 Hz,and a quasi-static hysteresis of only 7.5%,which is less than that of PSAs(>10%).With the constructed laser beam deflection system,a circular trajectory is realized,which has the potential for beam steering.
文摘We present an experimental study on tilt-tip（TT） and phase-locking（PL） control in a coherent beam combination（CBC） system of adaptive fiber laser array.The TT control is performed using the adaptive fiber-optics collimator（AFOC）,and the PL control is realized by the phase modulator（PM）.Cascaded and simultaneous controls of TT and PL using stochastic parallel gradient descent（SPGD） algorithm are investigated in this paper.Two-fiber-laser-,four-fiber-laser-,and six-fiber-laser-arrays are employed to study the TT and PL control.In the cascaded control system,only one high-speed CMOS camera is used to collect beam data and a computer is used as the controller.In a simultaneous control system one high-speed CMOS camera and one photonic detector（PD） are employed,and a computer and a control circuit based on field programmable gate array（FPGA） are used as the controllers.Experimental results reveal that both cascaded and simultaneous controls of TT using AFOC and PL using PM in fiber laser array are feasible and effective.Cascaded control is more effective in static control situation and simultaneous control can be applied to the dynamic control system directly.The control signals of simultaneous PL and TT disturb each other obviously and TT and PL control may compete with each other,so the control effect is limited.
