基于双腔光力系统实现不同频率多场纠缠

考虑在一个振动膜置于法布里-珀罗腔中间位置形成的双腔光机械系统中,当腔场的自由频谱宽度与腔镜谐振频率相比拟时,从两侧各注入单个强泵浦场,通过求解海森堡-朗之万方程来分析系统内多光场的纠缠特性。研究结果表明,利用该双腔光力系统,基于光场辐射压产生的腔场与腔镜耦合可方便地制备具有较大频率差的多光场纠缠,且在室温甚至更高温度下仍然可获得较强纠缠。该方案为实现频率相差很大的连续变量多光场纠缠制备提供了一种简便有效的方法。     

Faraday-rotation self-interference method for electron beam duration measurement in the laser wakefield accelerator

Real-time single-shot measurement of the femtosecond electron beam duration in laser wakefield accelerators is discussed for both experimental design and theoretical analysis that combines polarimetry and interferometry.The probe pulse polarization is rotated by the azimuthal magnetic field of the electron beam and then introduced into a Michelson-type interferometer for self-interference. The electron beam duration is obtained from the region size of the interference fringes, which is independent of the pulse width of the probe laser. Using a larger magnification system or incident angle, the measurement resolution can be less than 1 fs.