Efficient Integrated Multimode Amplifiers for Scalable Long-Haul SDM Transmission
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsJoseph M. KAHN, Hrishikesh SRINIVAS, Oleksiy KRUTKO
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Abstract
An integrated, high-performance amplifier subsystem is based on an optimized design of a multimode erbium-doped fiber amplifier (MM-EDFA) and a wavelength- and mode-selective pump coupler (PC). The length and ring doping profile of the MM-EDF and the pump-mode powers can be optimized to obtain low mode-dependent gain (MDG), low noise figure (NF) and high power-conversion efficiency (PCE). The pump coupler can be designed with high pump-mode efficiency and low signal-mode loss by appropriate selection of the pump mode group and the index exponent of an intermediate graded-index (GI) coupling fiber.
Claims21
An optical fiber amplifier subsystem, comprising:
- an optical fiber selected from the group consisting of a multimode fiber (MMF) and a coupled-core multi-core fiber (CC-MCF);
- a gain medium configured to provide gain for Nse guided signal spatial modes in the optical fiber;
- at least one pump light source configured to provide pump light at a pump wavelength to the gain medium;
- a pump coupler configured to perform propagation constant matching to effect mode-selective evanescent field coupling of the pump light to Npe guided pump modes in the optical fiber, where Nse is an integer specifying a number of guided signal spatial modes to be excited and Npe is an integer specifying a number of guided pump spatial modes to be excited, and Npe<Nse and Npe>1.
A spatial-division multiplexing (SDM) optical transmission system, comprising:
- first and second terminals;
- an optical path operatively coupling the first terminal to the second terminal and including at least one optical fiber configured to support a plurality of spatial modes at a given optical wavelength;
- and
- at least one multimode optical amplifier subsystem disposed along the optical path for amplifying the plurality of spatial modes propagating in the optical fiber, the at least one multimode optical amplifier subsystem including:
- a gain medium configured to provide gain for Nse guided signal spatial modes in the optical fiber;
- at least one pump light source configured to provide pump light at a pump wavelength to the gain medium;
- a pump coupler configured to perform propagation constant matching to effect mode-selective evanescent field coupling of the pump light to Npe guided pump spatial modes in the optical fiber,
- where Nse is an integer specifying a number of guided signal spatial modes to be excited and Npe is an integer specifying a number of guided pump spatial modes to be excited, and Npe<Nse and Npe>1.
Dependencies are inferred from the claim text.