Polski

Scientists develop flat-topped laser beams to overcome Gaussian distribution limitations

717
2023-08-04 16:39:10
Zobacz tłumaczenie

The beam emitted by almost all laser systems follows the Angle pattern of Gaussian distribution. The Gaussian irradiance distribution means that irradiance has a smooth peak at the center point and slowly declines toward the edge. In theory, the irradiance level of a Gaussian distribution can never reach zero, which means that the distribution can expand indefinitely. This phenomenon in the laser beam results in a large amount of light energy being wasted. However, for a variety of practical applications, we need a laser beam system that minimizes light energy waste. To solve this problem, flat-topped laser beams have been developed to overcome the limitations of Gaussian distribution and provide a beam distribution with sharp edges and uniform irradiance.

The role of DOE in beam shaping

Since a laser beam naturally does not exhibit a flat-topped beam profile, we need to convert a Gaussian beam to a flat-topped beam using an add-on or a beam shaper. This modification enables the beam profile to be used for a variety of laser applications. Analytical beam shaper and diffuser Beam shapers are the two main types of flat-top laser beam shapers.

 

A DOE (or diffractive Optical element) is an analytical beam shaper consisting of a single element designed to change the wavefront of a beam. DOE is a computer-generated hologram (CGH) combined with a specific delay topology that exploits the properties of light waves. The structure of the DOE can be designed to perform complex changes to coherent beams, such as laser beams.

 

Diffractive optical elements (DOE) introduce precise phase transitions for the beam. As the beam propagates, this phase transition produces a smooth, flat-topped irradiance distribution at the focal point. The shape of the profile can be customized on request, such as round, square, rectangular or straight.

 

Therefore, the main advantage of using such beam shapers is their excellent performance in terms of coherent beams such as TEM00 Gaussian beams with low M2 values. This type of input coherent beam has important applications in the laser material processing industry. In contrast, the use of diffuse elements as beam shapers is common in multi-mode, low-coherence laser beams.

 

DOE beam shaper Settings

The setup of the beam shaper consists of a laser beam entering the DOE and a focusing lens (such as an F-Theta lens) placed behind the DOE. The aim is to reproduce the far field of DOE in the focal plane. The beam shaper performs best when the through-light aperture of the lens is twice or more that of the DOE and the lens has no aberrations.

 

Application field

Flat-topped laser beam profiles have important applications in various industries such as semiconductors and microelectronics, where these beam irradiance profiles can be used for tasks such as drilling, copper removal, and contact scribing. The top hat laser beam also has important applications in high-tech manufacturing, green energy industry, especially laser metal processing industry.

 

Source: Laser Network

Powiązane rekomendacje
  • Micro ring resonators with enormous potential: hybrid devices significantly improve laser technology

    The team from the Photonic Systems Laboratory at the Federal Institute of Technology in Lausanne has developed a chip level laser source that can improve the performance of semiconductor lasers while generating shorter wavelengths.This groundbreaking work, led by Professor Camille Br è s and postdoctoral researcher Marco Clementi from the Federal Institute of Technology in Lausanne, represe...

    2023-12-11
    Zobacz tłumaczenie
  • Researchers have developed a QCL DFB continuous laser for gas detection

    Alpes Laser was founded in 1998 in Nazhatel, Switzerland and was the first company to bring quantum cascade lasers to the market. It released its first continuous laser in 2001 and its first high gain laser in 2009, thus maintaining this priority position.In 2004, the first commercial laser was introduced.Principle: In a single mode laser, the grating is etched into the active region to force the ...

    2023-08-16
    Zobacz tłumaczenie
  • Researchers have captured the strange behavior of laser induced gold

    A new study conducted by the US Department of Energy's SLAC National Accelerator Laboratory has revealed the strange behavior of gold when impacted by high-energy laser pulses.When certain materials are subjected to strong laser excitation, they will quickly disintegrate. But gold is exactly the opposite: it becomes more resilient and resilient. This is because the way gold atoms vibrate together ...

    2024-02-17
    Zobacz tłumaczenie
  • WVU engineers develop laser systems to protect space assets from the impact of Earth orbit debris

    The research from the University of West Virginia has been rewarded, as debris scattered in planetary orbits that pose a threat to spacecraft and satellites may be pushed away from potential collision paths by a coordinated space laser network.Hang Woon Lee, director of the Space Systems Operations Research Laboratory at the University of West Virginia, said that artificial debris dumps, including...

    2023-10-10
    Zobacz tłumaczenie
  • Technology Frontiers | What is the Next Generation Laser?

    Since the 1960s, lasers have brought revolutionary changes to the world and have now become an indispensable tool in modern applications, from cutting-edge surgical procedures and precision manufacturing to fiber optic data transmission. However, with the increasing demand for laser applications, challenges have also arisen. For example, the market for fiber lasers is constantly expanding, mainly ...

    2024-06-21
    Zobacz tłumaczenie