a polyimide for optical communications , which is expressed by the formula , a method of preparing the same , and a method of forming multiple polyimide films using the polyimide , wherein the formula is given by x 1 , x 2 , x 3 , a 1 , a 2 , b 1 , b 2 , b 3 , d 1 , d 2 , e 1 , e 2 , y 1 , y 2 , y 3 , y 4 , y 5 , y 6 , y 7 , and y 8 , are independently selected from the group consisting of hydrogen atom , halogen atom , alkyl group , halogenated alkyl group , aryl group and halogenated aryl group ; z is a simple chemical bond or selected from the group consisting of — o —, — co —, — so 3 —, — s —, — m —, — m — and — m —, wherein t is alkylene or arylene group substituted by at least one of halogen atom and halogenated alkyl group and m is an integer from 1 to 10 ; and n is an integer from 1 to 39 . because the polyimide expressed by the formula has a lower birefringence than a common polyimide used as a material for optical waveguiding , a problem associated with the dependency of optical characteristics on polarization can be solved . also , the solubility of the polyimide in an organic solvent is lowered , so that the occurrence of cracks in a polyimide layer can be avoided in the case of forming multiple polyimide films .