A method of propagating a laser signal through an optical waveguide and a waveguide laser system provide a novel way of stabilizing the beam emitted by a fiber laser system above the mode instability threshold wherein the beat length of two or more interfering transverse modes of the laser signal in the optical waveguide is modulated in time.

A laser medium unit includes: a plate-shaped laser gain medium which includes a first surface and a second surface opposite to the first surface and generates emission light by the irradiation of excitation light from the first surface; a reflection member that is provided on the second surface so as to reflect the excitation light and the emission light; and a cooling member that cools the laser gain medium. The laser gain medium includes an irradiation area which is irradiated with the excitation light and an outer area which is located outside the irradiation area when viewed from a thickness direction intersecting the first surface and the second surface. The cooling member is thermally connected to the second surface through the reflection member so that a cooling area of the laser gain medium is formed on the second surface.

Herein is provided a fiber length including a doped fiber core extending over the fiber length. First and second cladding regions radially surround the core. At least one pump light input site is arranged to accept input pump light into the first cladding region. A low-absorption length over which the first cladding region has a first cross-sectional geometry produces a first level of absorption of input pump light from the first cladding region to the core, extending from a pump light input site for an extent over which the doped core can absorb at least about 10% of input pump light from the first cladding region. A high-absorption section over which the first cladding region has a second cross-sectional geometry produces a second level of absorption of input pump light from the first cladding region to the core, greater than the first level of absorption of input pump light.

To solve the problem that the power consumption of optical amplifiers is not optimized over the life time of an amplifier, the optical amplifier includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores, a monitor that monitors the temperature of the optical amplifier and producing a monitoring result, a first light source that emits a first light beam to excite the cladding area, a second light source that emits a plurality of second light beams to excite each of the plurality of cores individually, and a controller that controls the first light source and the second light source based on the produced monitoring result.

A method of propagating a laser signal through an optical waveguide and a waveguide laser system provide a novel way of stabilizing the beam emitted by a fiber laser system above the mode instability threshold wherein the beat length of two or more interfering transverse modes of the laser signal in the optical waveguide is modulated in time.

According to an aspect of an embodiment, operations may include obtaining a respective target temperature for each respective segment of multiple segments of a Highly Non-Linear optical Fiber (HNLF). Each respective target temperature may be based on a respective Zero-Dispersion Wavelength (ZDW) distribution of its corresponding segment and may be based on a target ZDW of the HNLF. The operations may also include adjusting a respective temperature of each respective segment that may be based on the respective target temperature of each respective segment such that each respective segment has a respective ZDW that is within a threshold of the target ZDW.

According to an aspect of an embodiment, operations may include obtaining a respective target temperature for each respective segment of multiple segments of a Highly Non-Linear optical Fiber (HNLF). Each respective target temperature may be based on a respective Zero-Dispersion Wavelength (ZDW) distribution of its corresponding segment and may be based on a target ZDW of the HNLF. The operations may also include adjusting a respective temperature of each respective segment that may be based on the respective target temperature of each respective segment such that each respective segment has a respective ZDW that is within a threshold of the target ZDW.