4.3 Experimental procedures

tens or hundreds meters in this experiment. It can also use the fiber optic cable to replace the optical path of Michelson interferometer. Thetypeofthe fiber optic cable in Michelson interferometer is showed as the Figure 2. The longer the fiber optic cable in L is, the better it will be underthe premise that does not leak light. As for the magnetic or electric field in L, its intensity and direction can be adjustedbetter, so that it is convenient to quantitative analysis. Of course, it can be made step by step;for instance, it is made gradually with different intensity and direction of the magnetic or electric field, such as making their direction vertical or parallel to the light, and so on.

FIGURE 2. The fiber optic cable type Michelson interferometer: P is light source; Q is interference screen; A and B is fiber optic cable; L is magnetic or electric field generator.

4.3 Experimental procedures

For the fiber optic cable type Michelson interferometer, at first, without opening L, let a laser beam send into the two fiber optic cable A and B at the same time, and adjust the interference screen to obtain the clear interference image. Then, opening L, if there is a change of interference fringes, to observe and analyze the relationship between the interference fringes and the intensity or direction of the magnetic or electric field. In addition, it can also test about the relationship between the interference fringes and the

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