利用磁场抑制双频激光器频差闭锁，对激光器增益介质区施加横向交互磁场抑制激光器频差失谐的方法对磁场源提出要求。以方体线圈产生磁场，理论分析其磁场分布及均匀磁场产生的条件。利用Ansoft Maxwell 软件仿真分析方体线圈磁场分布，仿真结果与理论相吻合。方体线圈可在较大范围内产生高均匀度的磁场，满足抑制频差闭锁及失谐中对磁场的要求。较之Helmholtz 线圈，方体线圈产生磁场在均匀度和均匀场区体积两方面具有明显优势。

Both restraining locking-in and detuning of frequency difference in dual-frequency laser with magnetic field propose the request for the magnetic field. The magnetic field distribution of cube coil- pairas well as the condition to get uniform magnetic field is deduced theoretically. The magnetic field of cube coil-pair is simulated with Maxwell software, which agrees with the theoretical calculation. The result shows that cube coil- pair can produce uniform magnetic field in a considerable area. Magnetic field produced by cube coil-pair meets the demand in the applications of frequency difference lock-in and detuning. Compared with Helmholtz coils, cube coil-pair has advantages in both uniformity and the uniform field range.