Patent ID: 6205164
Filing Date: 2001-03-20
Classification: H01S

Abstract:
An optical amplifier that uses Er.sup.3+ ions as an amplification active elements, comprising:means for launching at least one light at a wavelength corresponding to an energy difference between .sup.4 I.sub.15/2 level and .sup.4 I.sub.11/2 level of said Er.sup.3+ ions, at least one light at a wavelength corresponding to an energy difference between .sup.4 I.sub.15/2 level and an energy level higher than said .sup.4 I.sub.11/2 level of said Er.sup.3+ ions, and at least one light to be amplified by an induced emission transition from .sup.4 I.sub.13/2 level to .sup.4 I.sub.15/2 level into an amplification medium doped with said Er.sup.3+ ions from the same direction.