What is a Fiber Laser?- A brief overview

Fiber lasers is that they can perform various functions that are key to industrial manufacturing with high precision and accuracy. The most important one Laser Cutting ,one of the fundamentals. 

The continuous wave (CW) Yb3+ doped fiber lasers are the most common in Laser Cutting machines as they are extremely powerful. A 01 µm fiber laser cutting machine can cut through high-strength steel easily. Not to mention most of the other metals and alloys.

Unlike traditional cutting machines with some mechanical cutter bound to wear off, these lasers don’t have such consumables. Hence, low maintenance saves energy, cost, and time in cutting processes. This can increase the profit margin for any industry.

Laser cutting is everywhere, from small-scale businesses to the giant automotive and aerospace industry. Fiber lasers are also inherently suitable for micromachining, done on a micro-scale. Thus, truly making it the face of modern manufacturing processes.

How Does the Fiber Laser Cutting Machine Work?

Fiber laser cutters use thermal cutting to cut through various metals and non-metals. It involves the following steps. 

First, a high-intensity laser beam is shot from the laser generator to the workpiece. The laser beam usually reaches a high temperature close to 10000-11000 ℃ (19500 ℉), enough to melt or vaporize any material. 

The details of the location and shape of the cut are fed through a numeric control system that guides the laser.

As the laser comes in contact with the material, it quickly melts or gasifies it, and pressurized auxiliary gas is blasted to the point of contact, which removes the debris. 

The process continues until the desired shape is achieved. 

Laser cutting machines come in many shapes and sizes, but the phenomenon behind their principal working is the same. Here are some of the crucial components of a laser cutting machine. 

1.  Machine Laser Source

The laser source is the heart of any laser-cutting machine. A separate unit usually creates a laser fed to the cutting head. Research shows that ytterbium Yb3+ doped fiber laser produces high-intensity lasers ranging from 900 nm to 1200 nm. Having a wide range of wavelengths means various materials can absorb the laser. 

This source is excellent for cutting High Strength, Carbon, Alloy, etc. It can = produce more than 10 KW of power that is intense enough to cut through thin plates (<5 mm) as well as 5 mm-40mm 

However, thulium Tm3+ and holmium Ho3+ doped fiber laser sources can cut non-metal and transparent materials. The source unit is attached to the main unit through heavy-duty connectors, amplifier plugs, encoder plugs, etc.

2.  Electrical components and Numeric Control System

The numeric control and the electronics are what you may call the “brains” of laser cutting machines. The main components are electrical servo motors, switches, operating systems, etc.

All the data about the characteristics of the laser beam and details of the soon-to-be machined part are entered here. 

A led control panel outside the machine gets data from the operator through computer-aided manufacturing (CAM) files.

This control system feeds all the data regarding output power, cutting speed, cutting angles, depth of cut, etc.

After that, it guides the control head and rails during the cutting process. With the advent of computer numeric control (CNC),

the precision of laser cutting is increased manifolds, so much so that the only limiting factor of laser cutting is the driving system.

3.  Gantry System and Auxiliary Parts 

Every industrial-sized fiber laser machine has a gantry system, a mechanized driveway that helps move the laser head in three-dimensional space.

The gantry system comprises rails, chains, and motors that help guide the laser head.

Constant research has been going on to improve the gantry system for fiber laser to reduce the machine time and improve efficiency.

Other parts include the working table(work tables) that holds the workpiece together.

Some fiber laser cutting machines have large tables that could compensate 12 meters long metal sheets and carry up to 9 tons of weight.

Many laser cutting machines also have an exhaust system that removes toxic gasses from the enclosure.

4.  Fiber Laser Cutting Head

The fiber laser cutting head is a device that shoots a laser onto the workpiece. It has a complex system of mirrors (traditional laser machines) or optical fibers that guide the laser beam through the nozzle. 

Nozzles are an important component of the laser head controlling the light beam. Not only does it directs the laser, but it also gives direction to discharge gas that blows off the molten material.

Nozzles can be adjusted manually and have a lot of influence on the cutting quality. It’s carefully calibrated before to prevent lack of penetration which can result in material melting.

Different diameter nozzles are used to cut various thicknesses.

The laser head is a moving part guided by a gantry system. Typical, the laser head can move in three-dimensional space.

But in special cases, laser heads are designed to move at a 45-degree angle, which helps create bevel shape cuts. These metal plates are meant to be welded later on. It saves much money, labor, and time otherwise spent on creating bevels. 

Other characteristics regulated by the laser head are beam intensity, beam focus position, cutting speed, cutting feed, gas pressure, etc.

The right cutting power, speed, and feed can make or break your manufacturing processes. Just like a traditional mechanical machine, a laser cutting machine comes with a detailed chart that defines the characteristics of a laser suitable to a particular material.

The whole working station is shielded by a metallic cover that gives the laser cutting machine an enclosed environment. This protects the laser beam and workpiece from external factors like air and dust. It also protects the human eyes as the invisible rays are hazardous.