We study the conditions of frequency modulation, spectral broadening, and amplification of a Gaussian pulse – a whispering-gallery-mode (WGM) wave packet (WP) – propagating along a spiral trajectory on the surface of an active cylindrical optical waveguide, in which a travelling refractive-index wave (TRIW) is generated. Analytical expressions are obtained for the dependences of the duration, chirp, and spectral width on the distance travelled by the pulse along the waveguide, as well as on the parameters of the waveguide and the radiation launched into it. It is shown that the interaction of a wave packet with the TRIW leads to a strong frequency modulation of the amplified pulse with the conserved linearity of the chirp. It is demonstrated that this circumstance can be used to generate pico- and subpicosecond pulses with peak powers above 100 kW.

我们研究了高斯脉冲的频率调制、光谱展宽和放大条件——一种回音壁模式 (WGM) 波包 (WP)——在有源圆柱形光波导表面上沿螺旋轨迹传播，其中产生一个折射率行波 (TRIW)。得到了持续时间、啁啾和光谱宽度对脉冲沿波导传播的距离以及波导参数和发射到其中的辐射的依赖关系的解析表达式。结果表明，波包与 TRIW 的相互作用导致放大脉冲的强频率调制与线性啁啾的守恒线性。已经证明，这种情况可用于产生峰值功率高于 100 kW 的皮秒和亚皮秒脉冲。