Articles about Optics and Photonics, Lasers, Fiber Bragg gratings and FBG sensors

High powered fiber lasers: the fiber laser has a fully tunable beam

on February 28, 2020

laser-cut-metal-4373878_640The newly developed high powered fiber laser provides real-time tuning of the laser beam characteristics directly from the output optical fiber using a fiber optic system. Laser systems have become indispensable tools for material processing, production, detection, protection, and scientific applications. 

This success is based on improved laser performance in several areas, including average and peak power, wavelength range, timeline flexibility (pulse duration and frequency, complex signals), efficiency, power stability, long-term reliability, maintenance, and operational requirements costs. 

High powered fiber lasers were especially important for implementing some of these achievements and currently dominate in many areas of industrial production and microprocessing. In addition to the efficiency and reliability inherent in fiber lasers, fiber laser systems generally provide fiber delivery to the processing head, minimizing the load on the fiber optics in free space in the laser and the machine.

The opportunity to tune a laser beam is important, for example, when cutting metal (the largest industrial application), so a low-power beam with relatively high radiation quality provides the highest speed for thin material, but the maximum thickness is limited by the resulting narrow cut, which prevents melt removal. 

A more powerful and more divergent laser beam (lower beam quality) allows cutting a thicker sheet with a corresponding reduction in speed compared to a thin sheet. During welding with high beam quality laser, welds with a “deep penetration channel” are formed, while larger spots with lower laser beam quality create shallow welds in the heat conduction mode, aesthetic welds on thin parts.

Besides, the specific shape of the beam affects the heat transfer and temperature gradients in the workpiece. Unlike a Gaussian beam, a flat-topped laser beam can prevent over or under processing by providing uniform radiation, and ring beams are known to improve processing quality in some applications.

Most laser systems provide the fixed characteristics of the beam. The laser beam can be converted to a different format using refractive or diffractive fiber optic systems. Fiber laser systems with a fixed beam can operate only in a limited range of processes or materials and thus, suffer from reduced productivity or limits. 

Customizable laser beam characteristics would be highly desirable to ensure process optimization and tool versatility. Various approaches have been developed that provide a certain level of beam tuning, including zoom lenses, switchable diffractive optical elements, deformable mirrors, laser beam combiners and (for fiber laser systems with a fiber radiation transport system) optical fiber connectors and switches with a motorized optics. 

Optromix is a fast-growing fiber laser manufacturer and a vendor of optical fiber sensors and optical monitoring systems. The company offers fast turnkey solutions and creates sophisticated fiber laser systems for special purposes. Optromix uses only its technologies and develops a broad variety of fiber lasers. If you have any questions or would like to buy a laser system, please contact us at info@optromix.com

editorHigh powered fiber lasers: the fiber laser has a fully tunable beam

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