Patent ID: 7440163
Filing Date: 2008-10-21
Classification: G02B,H01S

Abstract:
1. An optical apparatus comprising: a first WDM filter that couples a signal and a pump laser beam of a first wavelength to an erbium-doped fiber amplifier where the signal is amplified, wherein the signal and the pump laser beam of a first wavelength are respectively projected onto the first WDM filter from two opposite sides through a free space; a first tap projecting a sample of the signal to a first photodiode that converts the sample into an electronic signal; a second WDM filter provided to project a pump laser beam of a second wavelength coupled in by a collimator to the erbium-doped fiber amplifier where the once-amplified signal is amplified again; a gain flattening filter (GFF) provided to enhance the twice-amplified signal; a second tap coupling a sample of the twice-amplified signal to a second photodiode that converts the sample into an electronic signal; and a substrate on which the first and second WDM filters, the first and second taps, and the gain flattening filter are integrated so that the signal, the once-amplified signal, the twice-amplified signal, the laser beams of the first and second wavelengths are projected to corresponding components through a free space.