shown against the bonding glue to both surfaces of the rig film is prepared the insertion loss of the rig film 1 with respect to the light of 1064 nm was 0 6 db a c surface sapphire substrate 2 of 11 mm u00d7 11 mm and 0 5 mm in thickness identical with the dimensions of the rig film was used as a radiation substrate an anti reflection coating with respect to 1064 nm light was applied to the sapphire substrate as well an anti reflection coating for glue not shown was provided on the rig film bonding surface of the radiation substrate and an anti reflection coating for air not shown on the other surface the rig film 1 and two sapphire substrates 2 bonded with an optical epoxy glue so that the sapphire substrate a rig film and a sapphire substrate are laminated in the mentioned order the absorption coefficient of the used bonding glue with respect to the 1064 nm light was about 0 08 cm u2212 1 and the thickness of the bonding glue layer 5 u03bcm the faraday rotator thus obtained was cut with a dicing saw into nine faraday rotator chips of 3 mm in square the manufacturing and evaluation of optical isolator the assembling of the optical isolator will now be described by using the example drawing in fig2 a and 2b.