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).
DEFINITION of 'Federal Income Tax'. A tax levied by the United States Internal Revenue Service (IRS) on the annual earnings of individuals, corporations, trusts and other legal entities. Federal income taxes are applied on all forms of earnings that make up a taxpayer's taxable income, such as employment earnings or capital gains.