有機非線形光学結晶加工面の時間的特性変化とその防止策

抄録

The ultraprecision diamond turning is the best way to obtain optical surfaces on organic nonlinear optical crystals of soft and brittle in nature. The machined surface on chalcone organic nonlinear crystal is apt to become opaque with the passage of time. This paper deals experimentally with the cause and prevention measure of this opaqueness on chalcone. The transmittance of chalcone decreases and the surface roughness increases with the time after diamond turning. This phenomena are due to the recrystallization of chalcone after cutting. The wet cutting method which puts a waterdrop on a diamond tool can reduce the phenomena. The polymer coating just after wet diamond turning can solve the surface property change of chalcone perfectly. The coating will be able to work as the anti-reflection coating.