为了产生多种激光横模,以前的系统相对比较复杂,而且一般只能产生基横模和低阶横模,很难产生高阶横模,同时也很难观察到模竞争中一个频率抑制另一个频率的变化过程。基于猫眼谐振腔激光器和频率分裂技术,提出了一种新型的激光原理综合实验系统。该系统利用猫眼逆向器作为He-Ne激光器的一个腔镜,通过调节猫眼逆向器中两镜片间距可输出包括基横模、低阶横模、高阶横模在内的十余种典型横模,并可完成纵模、偏振、出光带宽等多种激光基本特性的实验。同时在基横模状态下,利用谐振腔内加入的石英晶体片可实现激光频率分裂及其频差调节。在此基础上又可实现完整的模竞争过程的观察。

The former laser systems are complex to realize multiple transverse modes. Only the fundamental mode and low-order modes can be generated, and the high-order modes are hard to be generated. Furthermore, the changing process of one frequency restraining another in mode competition is hard to be observed. A novel synthetical demonstration system of laser principle is presented based on a cat-eye cavity laser and the frequency splitting technology. In the system, a cat-eye retroreflector is treated as the cavity mirror of a He-Ne laser. More than ten typical transverse modes including fundamental mode, low-order modes, and high-order modes can be generated by adjusting the distance between two lenses in the retroreflector. In addition, more experiments of fundamental laser characteristics, such as longitudinal mode, laser polarization, and lasing bandwidth, are also carried out. In the condition of fundamental transverse mode, with a quartz crystal plate put in the cavity, laser frequency splitting and frequency difference adjusting can be achieved. Based on it, the dynamic process of mode competition can be observed.