A photonic crystal fiber (PCF) preform, from which a photonic crystal
fiber is manufactured, includes a rod-shaped substrate with holes
longitudinally formed therethrough in a photonic lattice structure, and
material layers having at least two different indices of refraction. The
material layers are disposed in the holes, respectively. Distribution of
index of refraction of the photonic crystal fiber preform is controlled
by arrangement of the material layers. Consequently, an optical fiber
with very low optical loss, very low optical nonlinearity and excellent
transmission characteristics can be easily manufactured, and an optical
fiber with various characteristics, differing depending upon the lattice
structure, can be realized.