Optical fiber amplifier with gain equalizing circuit
First Claim
1. An optical fiber amplifier comprising:
- an optical fiber amplifying section having an Er-doped optical fiber;
a gain equalizing section provided at a secondary stage of said optical fiber amplifying section, said gain equalizing section comprising a filter rotating means; and
an optical filter unit for compensating for wavelength dependent characteristics of a signal gain at said optical amplifying section, said optical filter unit comprising at least two optical filters each of which is a transparent multi-layer film with a layer of high refractive index and a layer of low refractive index being alternately and repeatedly stacked, each of said at least two optical filters being rotatably carried by said filter rotating means such that the wavelength transmission characteristics of said optical filter are set by changing an angle of incidence of a signal beam with respect to said optical filter unit and the wavelength dependency characteristics of said signal gain are compensated for.
1 Assignment
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Accused Products
Abstract
An optical fiber amplifier includes an optical amplifying section having an Er-doped fiber. A gain equalizing section is provided at secondary stage of the optical amplifying section and has an optical filter unit for compensating for wavelength dependency characteristics of a signal gain at the optical amplifying section. The gain equalizing section has a filter rotating device and the optical filter unit has et least two optical filters of transparent multi-layer film in which a layer of high refractive index and a layer of low refractive index are alternately and repeatedly stacked. The optical filter is rotated by the filter rotating device such that the wavelength transmission characteristics of the optical filter are set by changing an angle of incidence of the signal light with respect to the optical filter and the wavelength dependency characteristics of the signal gain are compensated for. The optical filter which is of the multi-layer film and which is rotatably arranged improves wavelength tunability.
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Citations
4 Claims
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1. An optical fiber amplifier comprising:
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an optical fiber amplifying section having an Er-doped optical fiber; a gain equalizing section provided at a secondary stage of said optical fiber amplifying section, said gain equalizing section comprising a filter rotating means; and an optical filter unit for compensating for wavelength dependent characteristics of a signal gain at said optical amplifying section, said optical filter unit comprising at least two optical filters each of which is a transparent multi-layer film with a layer of high refractive index and a layer of low refractive index being alternately and repeatedly stacked, each of said at least two optical filters being rotatably carried by said filter rotating means such that the wavelength transmission characteristics of said optical filter are set by changing an angle of incidence of a signal beam with respect to said optical filter unit and the wavelength dependency characteristics of said signal gain are compensated for. - View Dependent Claims (2, 3, 4)
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Specification