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).
Income tax is the single largest source of government revenue, making up about 30% of the total, followed by National Insurance contributions at around 20%. Each person has an income tax personal allowance, and income up to this amount in each tax year is free of tax. For the 2015/16 tax year, the tax-free allowance for under-65s with income less than Â£100,000 is Â£10,600.