MULTISTAGE OPTICAL AMPLIFIER

摘要

PURPOSE: To enhance the performance of an erbium doped fiber amplifier by interposing an optical means between the first and second stages a doped optical amplification fiber designed to receive a pump signal with pump wavelength. CONSTITUTION: An optical signal to be amplified is coupled with an input port 22 and a pump signal is coupled with pump ports 36, 32. Erbium doped fiber amplifiers 18, 19 on the first and second stages of an optical fiber amplifier 10 can be pumped from one or both ends thereof. Consequently, a laser diode and a multiplexer for pumping the first and second stages of the optical fiber amplifier 10 can be fabricated on a single substrate which includes one or a plurality of passive optical elements, e.g. optical isolator or optical filter.