1. optical glass: optical glass has high light transmittance and good mechanical strength, and can be used to make high-precision groove optical coupler code discs.

2. Optical polymer: Optical polymer has high light transmittance and strength to cooperate with metal. In some cases, it can replace optical glass to make groove optical coupler code disk.

3. Ceramic material: Ceramic has high hardness and high temperature resistance, and is suitable for high temperature environment or occasions requiring high mechanical strength.