rugate
/ˈruːɡeɪt/adjective
1 Botany and Zoology. Characterized by wrinkles or ridges; wrinkled.
2 Optics. Of a filter, coating, etc.: having a refractive index which varies smoothly in a regular, typically sinusoidal, manner with depth.
- Such filters can be used for blocking a narrow band of wavelengths..
Origin
Mid 19th century; earliest use found in James Dana (1813–1895), geologist, zoologist, and teacher. From classical Latin rūgātus having a wrinkled surface from rūga + -ātus.