We report the results of a study of a multimode semiconductor laser gyroscope (MSLG) with a long fibre-optic ring cavity (RC) and alternating frequency dithering formed by a lithium niobate phase modulator, and discuss the factors that determine the device operation. The fundamental limitations in MSLG operation are phase fluctuations and the multimode nature of radiation. Phase fluctuations caused by spontaneous emission of photons in a semiconductor optical amplifier (SOA) result in a slow drop in the beat amplitude. However, its complete decay does not occur due to the periodic and short-term lock-in phenomenon, which leads to the equalisation of the fluctuation levels in pairs of counterpropagating waves (PCPWs) that form the RC modes, and, thereby, to the restoration of the beat amplitude. The limitations associated with the multimode lasing regime are overcome due to the fact that the emission spectrum consists of a small number of narrow lines, and the positions of the antinodes and nodes of standing waves in the SOA field distribution coincide or are close. Both factors lead to the mode locking in spectral lines and, as a consequence, to synchronisation of PCPW beats at the device output. The mechanism of the formation of these factors is not yet clear.

我们报告了具有长光纤环形腔 (RC) 和由铌酸锂相位调制器形成的交变频率抖动的多模半导体激光陀螺仪 (MSLG) 的研究结果，并讨论了决定设备操作的因素。MSLG 操作的基本限制是相位波动和辐射的多模性质。由半导体光放大器 (SOA) 中光子的自发发射引起的相位波动会导致拍幅缓慢下降。然而，由于周期性和短期锁定现象，它不会发生完全衰减，这导致形成 RC 模式的成对反向传播波 (PCPW) 的波动水平均衡，从而使节拍幅度的恢复。由于发射光谱由少量窄线组成，并且 SOA 场分布中驻波的波腹和节点的位置重合或接近，因此克服了与多模激光方案相关的限制。这两个因素都会导致谱线中的锁模，从而导致设备输出端 PCPW 节拍的同步。这些因素的形成机制尚不清楚。