English

Researchers have discovered a new method to improve the resolution of laser processing

176
2024-03-28 13:52:54
See translation

Customized laser beams focused through transparent glass can generate a small dot inside the material. Researchers from Northeastern University have reported a method of using this small spot to improve laser material processing and increase processing resolution.


Their research results are published in the journal Optics Letters.

Laser processing, like drilling and cutting, is crucial in industries such as automobiles, semiconductors, and pharmaceuticals. The pulse width of an ultra short pulse laser source ranges from picoseconds to femtoseconds, and can be accurately processed in the range of micrometers to tens of micrometers. But recent progress requires smaller scales, below 100 nanometers, which is difficult to achieve with existing methods.

Researchers focus on laser beams with radial polarization, known as vector beams. The beam generates a longitudinal electric field at the focal point, resulting in a smaller spot than traditional beams.

Scientists have determined that this process has great potential in laser processing. However, one drawback is that due to the light refraction at the air material interface, the field weakens inside the material, thereby limiting its use.

"We overcame this by using oil immersion lenses to laser process glass substrates," exclaimed Yuichi Kozawa, Associate Professor at the Institute of Advanced Materials Multidisciplinary Research at Northeastern University and co-author of the paper. "Because the refractive indices of oil immersed and glass are almost the same, the light passing through them will not bend."

Further research on the behavior of radially polarized beams under circular focusing indicates that the longitudinal field is greatly enhanced. This enhancement is due to total reflection occurring at high convergence angles on the back between glass and air. By using a circularly polarized beam of light, Kozawa and his colleagues created a small focal point.

From there, they applied this method to processing glass surfaces with ultra short pulse laser beams. A single shot of the converted pulse on the back of the glass substrate will produce a hole with a diameter of 67 nanometers, approximately 1/16 of the wavelength of the laser beam.

"This breakthrough makes it possible to use enhanced longitudinal electric fields for direct material processing with higher accuracy," Kozawa added. "It provides a simple method to achieve processing scales below 100 nanometers and opens up new possibilities for laser nanoprocessing in various industries and scientific fields."

Source: Laser Net

Related Recommendations
  • NASA's laser reflector instrument helps to accurately locate Earth measurements

    The most famous use of GPS satellites is to help people understand their location, whether it is driving cars, ships or planes, or hiking in remote areas. Another important but little-known use is to distribute information to other Earth observation satellites to help them accurately locate measurements of our planet.NASA and several other federal agencies, including the US Space Force, the US Spa...

    2023-12-12
    See translation
  • Ultra thin two-dimensional materials can rotate the polarization of visible light

    For centuries, people have known that light exhibits wave like behavior in certain situations. When light passes through certain materials, they can change the polarization of light waves (i.e. the direction of oscillation). The core components of optical communication networks, such as optical isolators or photodiodes, utilize this characteristic. This type of component allows light to propagate ...

    2024-04-27
    See translation
  • Laser beam combined with metal foam to produce the brightest X-ray

    According to the Physicists' Network, scientists from Lawrence Livermore National Laboratory (LLNL) in the United States ingeniously combined the high-power laser emitted by the National Ignition Facility (NIF) with the ultra light metal foam to create the brightest X-ray ever. These ultra bright high-energy X-rays play an important role in many research fields, including imaging of extremely dens...

    01-18
    See translation
  • Shanghai Optics and Machinery Institute has made progress in the development of picosecond reflectors based on composite materials

    Recently, the High Power Laser Element Technology and Engineering Department of the Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences, has made progress in the research of picosecond reflectors based on composite materials. The relevant research results are titled "Hybrid material based mirror coatings for picosecond laser applications" and published in Optics and Laser Techn...

    2024-06-12
    See translation
  • The company has made key breakthroughs in the development of laser micromachining systems

    3D-Micromac AG, a provider of laser micromachining systems, has announced new advances in laser micromachining solutions for magnetic sensors, micro-leds, manufactured power devices and advanced packaging of semiconductors.Since the first working laser came out more than 60 years ago, lasers have been widely used in the industrial market. Uwe Wagner, CEO of 3D-Mircomac, said: "In the semic...

    2023-08-04
    See translation