emission vacuum spectrometer
发射真空分光计

• focus ring
• focus shift
• fog
• fog density
• fogged
• foggy environment
• fog penetrating viewing system
• fog resistant gloass
• fog restrainer
• foil
• Fokker-Plank equation
• fold
• folded cavity
• folded filter
• folded laser
• folded lobe large optical cavity
• folded path zoom lens
• folded stereoscopic viewer
• folded three-mirror cavity
• folding camera
• folding mirror
• folding rule
• fold-over
• follower
• follow focus attachment