optical crown
Học thuậtThân thiện
Definition
Noun: - A type of optical glass: Optical crown is a specific category of glass used in lenses and optical instruments. It is characterized by having both a low refractive index and low dispersion. This combination of properties makes it valuable for reducing optical aberrations like chromatic aberration, where different colors of light focus at different points.
Usage
- In optical engineering and lens manufacturing: The term is used to specify the material properties of glass components.
- The objective lens was made from optical crown to ensure minimal color fringing.
- For this achromatic doublet, the designer paired a flint glass element with an optical crown element.
Advanced Usage
- In compound terms: While "optical crown" itself is a noun phrase, it is often part of more specific technical compound names.
- Borosilicate crown glass is a common type of optical crown.
- The specifications called for a specific grade of optical crown, known as BK7.
Variants and Related Words
- Crown glass: A broader historical and technical term for glass with similar properties (low dispersion). "Optical crown" is a more specific modern term within this category.
- Flint glass: A contrasting type of optical glass with high dispersion and high refractive index, often paired with crown glass in lens systems.
- Achromatic lens: A lens design that often uses a combination of crown and flint glass elements to correct chromatic aberration.
Synonyms
- Low-dispersion glass: A descriptive synonym focusing on a key property.
- Crown glass (in an optical context): A closely related term, though "crown glass" can also refer to a historical glassmaking technique.
Related Phrases and Compounds
- Optical crown glass: A fuller, more explicit form of the term.
- Crown-flint pair: Refers to the standard combination of these two glass types in a lens element.
Noun
- optical glass of low dispersion and low refractive index