US 2016/0104995 A1 · SYSTEM AND METHOD FOR A DELIVERY FIBER FOR ISOLATION AGAINST BACK REFLECTIONS

Abstract

An apparatus and method that provide optical isolation by permitting substantially all forward-propagating light into a delivery fiber from an optical amplifier and substantially preventing backward-traveling light from the delivery fiber entering the optical amplifier without the use of a conventional optical isolator. Eliminating the isolator improves efficiency and reduces cost. Some embodiments use a delivery fiber having a non-circular core in order to spread a single-mode signal into multiple modes such that any backward-propagating reflection is inhibited from reentering the single-mode amplifier. Some embodiments amplify an optical signal in a gain fiber having an output end, output the forward-propagating amplified signal as a high-brightness optical beam (having a first Rayleigh range) into a removable delivery fiber having a non-circular waveguide, output the amplified signal from a distal end of the delivery fiber, and, without the use of a non-linear optical isolator, inhibit backward-propagating light from re-entering the gain fiber.

Claims20

Dependent claims

A method comprising:

amplifying an optical signal in an optical-gain-fiber subsystem of a laser system, wherein the optical-gain-fiber subsystem includes an output end;
outputting the amplified optical signal in a forward-propagating direction from the output end of the optical-gain-fiber subsystem;
receiving the amplified optical signal from the output end of the optical-gain-fiber subsystem into a first end of a delivery fiber;
outputting the amplified optical signal from a second end of the delivery fiber;
and
without the use of a non-linear optical isolator, inhibiting light traveling in a backward-propagating direction in the delivery fiber from entering the optical-gain-fiber subsystem in the backward-propagating direction, wherein the inhibiting includes tilting an optical axis of the first end of the delivery fiber relative to a light-propagation axis of the amplified optical signal exiting the optical-gain-fiber subsystem such that a non-zero angle is formed between the tilted optical axis of the first end and the light-propagation axis of the amplified optical signal.

3 more elements

An apparatus comprising:

an optical-fiber amplifier subsystem configured to amplify an optical signal, wherein the optical-fiber amplifier subsystem includes an output end, and wherein the output end of the optical-fiber amplifier subsystem is configured to output the amplified optical signal in a forward-propagating direction;
and
a delivery fiber that has an interface to the optical-fiber amplifier subsystem and that has a first end and a second end, wherein the delivery fiber is configured to receive the optical signal from the output end of the optical-fiber amplifier subsystem into the first end of the delivery fiber, wherein the delivery fiber is configured to output the optical signal from the second end of the delivery fiber, and wherein an optical axis of the first end of the delivery fiber is tilted relative to a light-propagation axis of the amplified optical signal exiting the optical-fiber amplifier subsystem such that a non-zero angle is formed between the titled optical axis of the first end and the light-propagation axis of the amplified optical signal and such that light traveling in a backward-propagating direction in the delivery fiber is inhibited from entering the optical-fiber amplifier subsystem.

Dependencies are inferred from the claim text.

System and method for a delivery fiber for isolation against back reflections

Life of this patent

System and method for a delivery fiber for isolation against back reflections

Life of this patent

Abstract

Claims20