US 5,706,125 A · Optical signal amplifying circuit

Abstract

A wide-band optical signal amplifying circuit having gain exhibiting less wavelength dependency for amplifying optical signal and analogue-modulated optical signal. The optical signal amplifying circuit includes one or a plurality of optical amplifiers for amplifying en bloc optical signal components of respective wave-lengths of a wavelength-multiplexed optical signal and a multi-cavity type or the like dielectric multilayer interference filter disposed at an input or output side of the optical amplifier or therebetween. The dielectric multilayer interference filter is stable over a wide band and exhibits a steep cut-off characteristic. The multi-cavity type dielectric multilayer interference filter has a center wavelength for transmission which is variable.

Claims2

Dependent claims

An optical signal amplifying circuit using an optical fiber amplifier, comprising:

at least one optical amplifier for amplifying en bloc optical signal components of respective wavelengths contained a wavelength-multiplexed optical signal;
a multi-cavity type dielectric multilayer interference filter disposed at an input side or alternatively at an output side of said optical amplifier or alternatively between said optical amplifiers when a plurality of said optical amplifiers are employed;
an optical level detector for detecting a level of light inputted to the optical signal amplifying circuit;
and
an optical filter controller, connected to said multi-cavity type dielectric multilayer interference filter and said optical level detector, for controlling said optical multi-cavity type dielectric multilayer interference filter in accordance with the detected input light level so as to have an optimum center wavelength for transmission.

2 more elements

Dependencies are inferred from the claim text.

Optical signal amplifying circuit

Life of this patent

Optical signal amplifying circuit

Life of this patent

Abstract

Claims2