Fiber optic speckle based interferometry for IR radiation sensing and intrusion monitoring systems

Abstract

In the previous paper we have reported a fiber optic method for registration of low intensity infrared radiation based on the effect of interference of propagation modes in the far field of a multimode fiber. In this paper we present new results on the method. We describe here a speckle based fiber-optic technique that can be used for IR radiation sensing as well as for intrusion-monitoring systems. The method is based on the effect of variation of the speckle pattern in the far-field of a multimode fiber under external perturbation of IR radiation.