Demonstration of the reliability of a 5-kW-level oscillating–amplifying integrated fiber laser

Abstract

A novel fiber laser called an oscillating–amplifying integrated fiber laser was studied experimentally, in which the oscillating section and amplifying section share the pump between them. Based on this configuration, a 5-kW fiber laser system with optical–optical efficiency of 80.9% and M 2 factor of 1.5 was achieved. The startup and shutdown sequence of the laser was studied in detail. When pumps of the laser were deliberately turned on in an inverted order, such as switching on/off the amplifying section before/after the oscillating section, which is normally disastrous in a classic fiber amplifier, the laser system turned out to operate stably at full power level. Thus, it is verified that there is no priority between the amplifier and the seed in this laser system. It combines the advantages of conventional fiber oscillators and fiber amplifiers, including high efficiency, high reliability, good anti-backreflection, and simple control logic.

Functional Fibers and Functional Fiber-Based Components for High-Power Lasers

“…With the development of fiber preform preparation and mechanical polishing technology, the studies of tapered fibers has evolved to more degrees of freedom along the longitudinal dimension, which is driven by better pump absorption capacity and greater single-mode potential. A series of representative results at several-kilowatt-level have been reported with near single-mode outputs [76,[258][259][260][261][262][263][264][265][266][267][267][268][269][270][271][272][273][274][275][276][277][278][279][280]. Table 2 summarizes the recent progress of tapered fibers for HPFLs applications.…”

A 3.7-kW Oscillating-Amplifying Integrated Fiber Laser Featuring a Compact Oval-Shaped Cylinder Package

“…In some application scenarios, fiber lasers are challenged by harsh environments and/or strong reflecting light. Recently, an oscillating-amplifying integrated fiber laser has been proposed [ 13 , 14 , 15 , 16 ], which has the advantages of high efficiency, environmental robustness, and anti-reflection [ 13 , 14 ]. A 5-kW oscillating-amplifying integrated fiber laser has previously been demonstrated in [ 16 ], which presents a new high-power laser structure for use in industrial applications.…”

“…Recently, an oscillating-amplifying integrated fiber laser has been proposed [ 13 , 14 , 15 , 16 ], which has the advantages of high efficiency, environmental robustness, and anti-reflection [ 13 , 14 ]. A 5-kW oscillating-amplifying integrated fiber laser has previously been demonstrated in [ 16 ], which presents a new high-power laser structure for use in industrial applications. In general, high-power fiber lasers have been laid on plane heat sinks to dissipate the waste heat [ 17 , 18 , 19 , 20 ]; a 4-kW fiber laser often needs to be laid on an area of 0.383 m 2 [ 21 ], which results in a large occupying area for the laser manufacturer, necessitating more investment and more cost [ 22 ].…”

Modified oscillating-amplifying integrated fiber laser for stimulated Raman scattering suppression

“…Oscillating-amplifying-integrated fiber laser was introduced in less than one decade, yet the output power underwent a rapid development [1,2,3]. Oscillating-amplifying integrated fiber laser combines the advantages including high efficiency [4], good tolerance to back reflection [3], conciseness in construction, and robustness in control logic [5]. However, high power pumping from the oscillating resulting in a strong seed into the amplifying segment, which would further lead to strong nonlinearity like stimulated Raman scattering (SRS), just as the newly published result of a 5-kW output from OAIFL [5].…”