法布里-珀罗腔型弱磁增敏气室结构

提高小型化无自旋交换原子磁力仪的灵敏度是目前弱磁探测研究的难点问题，为解决这个难题提出一种基于法布里-珀罗腔的增敏气室结构。通过法布里-珀罗腔谐振原理和激光传输矩阵，在理论分析与数值计算方面对出射激光的光旋角倍增效果进行了研究。理论和仿真结果表明，随着激光在腔内往返传输次数的增加，倍增因子在初始阶段近线性增长然后缓慢趋于一个最大值，该最大值在理想状态下为16且由腔的结构参数决定。另外，碱金属原子自旋碰撞导致的吸收和腔体失谐会以不同的方式降低倍增因子，仿真结果表明:当失谐量为π/32时，倍增因子减少幅度接近50%。提出的这种腔增强型气室结构易于集成，为提高原子磁力仪的灵敏度和深入理解碱金属气室内的自旋碰撞提供了新的思路。

Structure of Fabry-Perot cavity type weak magnetic sensitivity enhancement vapor cell

Enhancing the sensitivity of the miniaturized spin exchange relaxation free (SERF) atomic magnetometer for weak magnetic detection research is a difficult problem at present. A structure of sensitivity enhanced vapor cell based on Fabry-Perot cavity was proposed to solve this problem. With the principle of Fabry-Perot cavity resonance and theory of light transmission matrix, the amplification factor of optical rotation angle of emitted laser was studied in theoretical analysis and numerical simulation. The results of theoretical analysis and numerical simulation show that as the number of laser transmission round trips in cavity increases, the amplification factor of output rotation angle increases linearly in the initial stage then tends to a maximum value. Ideally, the maximum value is 16 and it is determined by the structural parameter of Fabry-Perot cavity. Besides, the absorption caused by alkali metal atoms spin collision and cavity off-resonance reduce the amplification factor in different ways. Numerical simulation results show that the reduction of amplification factor is close to 50%, while the off-resonance is π/32. This sensitivity enhanced vapor cell is easy to integrate, and provides a new perspective of sensitivity enhanced atomic magnetometer and thoroughly understanding of spin collision in alkali metal vapor cell.