PURPOSE: To obtain the hologram which has a high modulation rate of a refractive index, is simple in developing process and is short in exposing time by dispersing microballs into a base polymer and incorporating a material which generate gas by a chemical reaction into these microballs.
CONSTITUTION: Polyvinyl alcohol (about 500 degrees of polymn.) is used for the base polymer and a polyester resin is used for the microballs as more specific examples. The microballs are incorporated at 30 pts.wt. into 70 pts.wt. base polymer. An adize compd.; 2, 6-bis(p-azide benzylidene) cyclohexanone is used as a gas generating agent and ketocumarine is used as a sensitizer. This gas generating agent is cracked by a laser beam and the generated gas forms extremely small voids in the microballs. The refractive index of the voids is nearly 1 and is extremely different from the refractive index of the base polymer. The hologram having a large change in the refractive index is thus obtd.
IMAHASHI SATOSHI
YAMADA YOZO
