An optical head has a first propagation section made of a first low extinction material and installed along an optical axis, a pair of second propagation sections which, being made of a second low extinction material, sandwich the first propagation section, a pair of first confining sections which, being made of a material with propagation capability lower than that of the second propagation sections, further sandwich the first propagation section and second propagation sections from outside the second propagation sections, and a pair of third propagation sections which, being made of a material with light propagation capability higher than that of the first confining sections, further sandwich the first confining sections from outside. Also, an optical head design apparatus calculates a complex propagation constant along an optical axis by solving an equation which is based on F matrices, and thereby design an optical head in a far-sighted manner.