Doped fiber amplifier (The typical representative: EDFA) Erbium-doped fiber amplifier (EDFA) is the most widely used fiber-optic amplifiers, mainly made of Erbium-doped fiber (EDF), pump light source, optical couplers, optical isolators, optical filters and other components.
Noun. 1. national income-the total value of all income in a nation (wages and profits and interest and rents and pension payments) during a given period (usually 1 yr).
What income means. Income means: 1  an amount you earn, derive or receive for your own use or benefit. 2  profits, the amount of earnings in excess of expenses, whether of a capital nature or not, and.  a periodic payment or benefit you receive as a gift or allowance.