Laser systems based on coherent beam combination(CBC) that rely on tiled pupil architecture intrinsically carry digital capabilities independently applicable to all three essential characteristics of a laser pulse: am...Laser systems based on coherent beam combination(CBC) that rely on tiled pupil architecture intrinsically carry digital capabilities independently applicable to all three essential characteristics of a laser pulse: amplitude, phase and polarization. Those capabilities allow the far-field energy distribution to be flexibly tailored in real time. Operation in the femtosecond regime at high repetition rates gives access to a wide range of applications requiring both high peak and average powers. We address the task of independent peak versus average power adjustment needed for applications seeking to decouple nonlinear phenomena associated with GW peak power from the thermal load inherent to kW average power operation. The technical solutions proposed are presented in the framework of the Ecole Polytechnique XCAN CBC laser platform(61 independent channels) with an emphasis on thermal management measures implemented to ensure its nominal operation.展开更多
Ultrahigh-speed imaging is an essential tool for capturing fast dynamic scenes across various fields.Despite the development of numerous technical strategies,achieving ultrahigh-speed imaging with high spatiotemporal ...Ultrahigh-speed imaging is an essential tool for capturing fast dynamic scenes across various fields.Despite the development of numerous technical strategies,achieving ultrahigh-speed imaging with high spatiotemporal resolution and substantial sequence depth remains a significant challenge.To address this issue,we present a compressive ultrahigh-speed imaging technique based on acousto-optic frequency sweeping,termed AOFSCUSI.AOFS-CUSI employs light with rapidly time-varying spectra generated by acousto-optic modulation to illuminate dynamic scenes,records spatio-spectral information using snapshot compressive imaging,and ultimately reconstructs spatiotemporal information through time-spectrum mapping.This technique achieves a temporal resolution of 1.55 million frames per second,a spatial resolution of 228 lp/mm,and a sequence depth of 31 in a single shot.We experimentally validate the superior performance of AOFS-CUSI by capturing the rotation of an optical chopper,the movement of microspheres in a microchannel,and the femtosecondlaser-induced cavitation bubble dynamics.By eliminating the requirement for ultrafast laser sources and simultaneously extending the temporal window,AOFS-CUSI offers an excellent solution for recording and analyzing various fast dynamics,presenting significant potential for applications in both fundamental and applied research.展开更多
基金funding from the European Innovation Council(Open grant No.101047223-NanoXCAN and Horizon 2020 Framework Programme 654148)the Agence de l’Innovation de Défense(AID)+1 种基金the Centre National des Etudes Spatiales(CNES)supported in part by the U.S.Department of Defense,Defense Threat Reduction Agency(HDTRA120-2-0002)
文摘Laser systems based on coherent beam combination(CBC) that rely on tiled pupil architecture intrinsically carry digital capabilities independently applicable to all three essential characteristics of a laser pulse: amplitude, phase and polarization. Those capabilities allow the far-field energy distribution to be flexibly tailored in real time. Operation in the femtosecond regime at high repetition rates gives access to a wide range of applications requiring both high peak and average powers. We address the task of independent peak versus average power adjustment needed for applications seeking to decouple nonlinear phenomena associated with GW peak power from the thermal load inherent to kW average power operation. The technical solutions proposed are presented in the framework of the Ecole Polytechnique XCAN CBC laser platform(61 independent channels) with an emphasis on thermal management measures implemented to ensure its nominal operation.
基金National Natural Science Foundation of China(12325408,12274129,12374274,12274139,62175066,92150102,62475070,12474404,12471368)Shanghai Municipal Education Commission(2024AI01007)+1 种基金Open Fund of Guangdong Provincial Key Laboratory of Nanophotonic Manipulation(202504)Guangdong ST Program(2023B1212010008).
文摘Ultrahigh-speed imaging is an essential tool for capturing fast dynamic scenes across various fields.Despite the development of numerous technical strategies,achieving ultrahigh-speed imaging with high spatiotemporal resolution and substantial sequence depth remains a significant challenge.To address this issue,we present a compressive ultrahigh-speed imaging technique based on acousto-optic frequency sweeping,termed AOFSCUSI.AOFS-CUSI employs light with rapidly time-varying spectra generated by acousto-optic modulation to illuminate dynamic scenes,records spatio-spectral information using snapshot compressive imaging,and ultimately reconstructs spatiotemporal information through time-spectrum mapping.This technique achieves a temporal resolution of 1.55 million frames per second,a spatial resolution of 228 lp/mm,and a sequence depth of 31 in a single shot.We experimentally validate the superior performance of AOFS-CUSI by capturing the rotation of an optical chopper,the movement of microspheres in a microchannel,and the femtosecondlaser-induced cavitation bubble dynamics.By eliminating the requirement for ultrafast laser sources and simultaneously extending the temporal window,AOFS-CUSI offers an excellent solution for recording and analyzing various fast dynamics,presenting significant potential for applications in both fundamental and applied research.
