红宝石激光单脉冲全息照像出现干涉条纹的讨论

A Study on the Appearance of Interferencelfringes at a Single exposure Huolgram Using a Ruby Pulse Laser

本文指出调Q红宝石激光器的单纵模选择是非常困难的。若激光器的两个相距较远的纵横同时振荡,纵虽用单脉冲一次照全息像,在其再现像上也会有干涉条纹出现。这种全息干涉条纹的出现实际上是相干长度呈现周期性的表现。只要采取相应措施保证单纵模运转,就可以消除这种现象。本文还指出提高相干度的办法。

It is very difficult to select the single longitudined mode in a Q-switched ruby laser. If two longitudinal mode are oscillated simultaneously in a laser cavity, inteference fringes woued appear on the reconctrueted image even though in making a hologram at a single exposure. These hologram interference fringes present the periodicity of coherence lenlth of the laser. Certain procedures can be adopted to acvoid the situation and ensuring single longitudinal mode operation. Hence all the interference fringe will be disappeared. The coherence of the laser is also discussed in this paper.