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US 6,549,331 B2Granted
Polarization insensitive semiconductor optical amplifier
AssigneeGenoa Corporation
InventorsJeffrey D. Walker, Sol P. Dijaili, Richard P. Ratowsky
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AssigneeGenoa Corporation
InventorsJeffrey D. Walker, Sol P. Dijaili, Richard P. Ratowsky
Estimating the term…
An optical amplifier module that is insensitive to polarization comprises a first fiber, a second fiber, a semiconductor optical amplifier (SOA), and a polarization dependent loss (PDL) unit. The first fiber provides for optical input to the SOA. The SOA amplifies the optical signal received and outputs the amplified signal. The output of the SOA is optically coupled to the PDL unit. The PDL unit provides polarization dependent loss and the loss is preferably selected to match the polarization dependent gain of the SOA such that when two are coupled there is no overall polarization dependence. The output of the PDL is optically coupled to the fiber for transmission output. The present invention also comprises a method for manufacturing an optical amplifier module that comprises the steps of: determining the polarization dependent gain of an SOA, determining the polarization dependent loss of a plurality of PDL units, selecting a PDL unit such that the polarization dependent loss when coupled to the SOA is reduced, and packaging the SOA and the PDL unit as an optical amplifier module.
A polarization insensitive semiconductor optical amplifier module, the module comprising:
A method for manufacturing a polarization insensitive semiconductor optical amplifier module, the method comprising the step of:
A polarization insensitive semiconductor optical amplifier module, the module comprising:
A polarization insensitive semiconductor optical amplifier module, the module comprising:
A method for manufacturing a polarization insensitive semiconductor optical amplifier module, the method comprising the steps of:
A polarization insensitive semiconductor optical amplifier module, the module comprising:
A polarization insensitive semiconductor optical amplifier module, the module comprising:
A polarization insensitive semiconductor optical amplifier module, the module comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Amplifier structures not provided for in groups H01S5/02 - H01S5/30: the arrangement being polarisation-insensitive
With a special facet structure, e.g. structured, non planar, oblique: oblique facets
Devices using the process of light amplification by stimulated emission of radiation
Term ended 2 Jun 2020 (estimated)
1. Field of the Invention
The present invention relates to optical communications systems. More particularly, the present invention relates to polarization independent optical amplifiers. Still more particularly, the present invention relates to a method for packaging semiconductor optical amplifiers that eliminates polarization dependence.
2. Description of the Background Art
The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings. The drawings are not necessarily done to scale.
FIG. 1 is a schematic diagram of a conventional semiconductor optical amplifier (SOA) including packaging.
FIG. 2 is a schematic diagram of a first and preferred embodiment of a packaged semiconductor optical amplifier (SOA) having polarization dependent loss constructed in accordance with the present invention.
The present invention will now be described with respect to a number of different embodiments. For each embodiment, like reference numerals are used to indicate like parts with the same or similar functionality for ease of understanding and convenience. Furthermore, the present invention is described below in the context of a gain-clamped semiconductor optical amplifier, however, the present invention is applicable to all types of semiconductor optical amplifiers. Nonetheless, the present invention is most advantageous with a gain-clamped semiconductor optical amplifier because the polarization dependent gain in the optical amplifier can be predetermined and is independent of the input optical signal since the gain is clamped.
Standard SOA Module
Referring now to FIG. 1, a block diagram of a conventional semiconductor optical amplifier module 10 is shown. The optical amplifier module 10 includes an input fiber 102, optics 108, 112, a semiconductor optical amplifier (SOA) 110, and an output fiber 106 together in a package 104. The input fiber 102 is optically coupled to the SOA 110 by optics 108 such as a lens. The SOA 110 is a conventional semiconductor optical amplifier chip. The SOA 110 provides in-line amplification and its output is optically coupled by optics 112 such as a lens to the output fiber 106. The light travels along the path generally illustrated by line 114. For example, the optical amplifier module 10 can be a 1901 SOA or a 1921 SOA manufactured-and sold by Acatel Telecom of Reston, Va. Such prior art SOA modules have a polarization sensitivity from 1 to 3 dB. Present day SOAs have been able to limit the polarization sensitivity only to 0.5 dB at best.