为了提高成像光纤的成像质量,消除成像光纤中不需要的模是极其重要的。众所周知,用弯曲法可减少不需要的模,但该方法涉及到光纤热处理,故似乎有些困难。因此,最近我们采用在拉丝过程中旋转预制棒的方法制造出扭绞成像光纤。从而发现,与普通光纤相比,该光纤的反差值可提高25％以上。 In order to improve the imaging quality of the imaging fiber, it is extremely important to eliminate the unwanted die in the imaging fiber. It is well known that bending can reduce unwanted modes, but the method involves fiber heat treatment and therefore seems somewhat difficult. Therefore, recently we have produced twisted twisted optical fibers by spinning the preform during drawing. It was found that, compared with ordinary optical fiber, the optical fiber can increase the contrast value of more than 25%.