What is a MOPA laser? At present, the types of pulsed fiber lasers used in laser marking on the market mainly include two types: Q-switching technology and MOPA technology. MOPA (Master Oscillator Power-Amplifier) laser refers to a laser structure in which a laser oscillator and an amplifier are cascaded. In industry, MOPA laser refers to a unique, more "intelligent" nanosecond pulsed fiber laser composed of a semiconductor laser seed source and fiber amplifier driven by electrical pulses. Its "intelligence" is mainly reflected in the independent adjustable output pulse width (the range can reach 2ns-500ns), and the repetition frequency can be as high as megahertz. The seed source structure of the Q-switched fiber laser is to insert a loss modulator in the fiber oscillating cavity, which generates a nanosecond pulse light output with a certain pulse width by periodically modulating the optical loss in the cavity. For this problem that often troubles everyone, we will make a simple analysis from the internal structure of the laser, output optical parameters and application scenarios.
mopa fiber laser marking machine
Output optical parameters of MOPA fiber laser
The output pulse width of MOPA fiber laser is independently adjustable. The pulse width of the MOPA fiber laser is arbitrarily tunable (ranging from 2 ns to 500 ns). The narrower the pulse width, the smaller the heat-affected area, and the higher the machining accuracy can be obtained. The output pulse width of the Q-switched fiber laser is not adjustable, and the output pulse width is generally unchanged at a fixed value of 80 ns to 140 ns. MOPA fiber lasers have a wider repetition frequency range. The repetition frequency of MOPA laser can reach the high frequency output of MHz. High repetition frequency means high processing efficiency, and MOPA can still maintain high peak power characteristics under high repetition frequency conditions. The Q-switched fiber laser is limited by the working conditions of the Q switch, and the output frequency range is narrow, and the high frequency can only reach ~100 kHz.
MOPA Fiber Laser Marking Machine
MOPA fiber laser has a wide range of parameter adjustment. Therefore, in addition to covering conventional nanosecond laser processing applications, it can also use its unique narrow pulse width, high repetition frequency, and high peak power to achieve some unique precision processing applications. for example:
Alumina sheet surface stripping application
Today's electronic products are getting thinner and lighter, and many mobile phones, tablets, and computers use thin and light alumina as the outer shell of the product. When using a Q-switched laser to mark conductive potential on a thin aluminum plate, it is easy to cause deformation of the material and produce a "convex hull" on the back, which directly affects the aesthetics of the appearance. The parameters of the MOPA laser with a smaller pulse width can make the material not easily deformed, and the shading will be more delicate and brighter. This is because the MOPA laser uses a small pulse width parameter to make the laser stay on the material shorter, and the energy is high enough to remove the anode layer, so for the process of stripping the anode on the surface of the thin aluminum oxide plate, MOPA Lasers are a better choice.
氧化铝打黑
Anodized Aluminum Blackening Application
Use laser to mark black trademark, model, text, etc. on the surface of anodized aluminum material. In the past two years, this application has gradually been widely used by electronics manufacturers such as Apple, Huawei, ZTE, Lenovo, Meizu, etc. for the shell of electronic products , used to mark the trademark, model, etc. of the black mark. For such applications, currently only MOPA lasers can process them. Since the MOPA laser has a wide range of pulse width and pulse frequency adjustment, the parameters of narrow pulse width and high frequency can be used to mark the black effect on the surface of the material, and different grayscale effects can also be marked by different parameter combinations.
Color Laser Marking
Color laser marking is a new type of laser marking process. At present, only MOPA lasers can mark color patterns on metal materials such as stainless steel, chromium, and titanium. When coloring the stainless steel material, the color change of the surface layer of the material can be changed by adjusting the laser beam, so as to obtain the decorative effect of different colors. For the stainless steel product industry, the color of the marking pattern can be added, and various kinds of Text pattern, convenient and easy to operate: environmental protection and no pollution; fast marking speed, which can greatly increase the added value of stainless steel products and enhance the market competitiveness of stainless steel products. Add added value to the product.
Electronics, semiconductor, ITO precision processing applications
In precision processing such as electronics, semiconductors, and ITO, fine scribing applications are often required. Due to its own structure, the Q-switched laser cannot adjust the pulse width parameters, so it is difficult to make fine lines. Since the MOPA laser can flexibly adjust the pulse width and frequency parameters, it can not only make the scribed lines fine, but also make the edges smooth and not rough.
