English

Scientists demonstrate powerful UV-visible infrared full-spectrum laser

517
2023-08-25 14:29:07
See translation
Figure: a. Schematic diagram of the HCF-LN-CPPLN experimental setup. W. CaF? Window M, mirror.
b. The bright white light circular spots emitted by the CPPLN sample.
c. The first-order diffraction beam of B displays a colorful rainbow pattern from purple to red.
d. The HCF-LN-CPPLN module generates normalized spectra of the output full spectrum laser signal through the second NL HHG and third NL SPM effects.
Source: Lihong Hong, Liqiang Liu, Yuanyuan Liu, Junyu Qian, Renyu Feng, Wenkai Li, Yanyan Li, Yujie Peng, Yuxin Leng, Ruxin Li, and Zhi-Yuan Li

High brightness ultra-wideband ultra-continuous white light laser has attracted more and more attention in physics, chemistry, biology, material science and other scientific and technological fields. Over the past few decades, many different methods have been developed to produce supercontinuous white lasers.

Most of them utilize a variety of third-order nonlinear effects, such as self-phase modulation (SPM) occurring in microstructured photonic crystal fibers or homogeneous plates, or noble gas-filled hollow fibers. However, the quality of these supercontinuum light sources is subject to some limitations, such as the small pulse energy at the nanojoule level, and the requirements of complex dispersion engineering.

Another more efficient means of expanding the laser spectral range is through the various second-order nonlinear effects (2nd-NL) of the quasi-phase matching (QPM) scheme. However, the spectrum and power scaling performance of these pure 2N-NL schemes are still poor due to the narrow pump band width, limited QPM operating bandwidth, and reduced efficiency of high order harmonic energy conversion.

How to solve these bad limitations in the 2nd-NL and 3rd-NL systems and make both to produce full-spectrum supercontinuum lasers with spectral coverage from ultraviolet to mid-infrared has become a great challenge.

In a new paper published in Light: Science & Applications: A team led by Professor Zhi-Yuan Li and colleagues from the School of Physics and Optoelectronics at South China University of Technology in China has demonstrated an intense, quadruple-frequency UV-Vis-IR full-spectrum laser source (300 nm to 5000 nm, peak value -25 dB) with an energy of 0.54 mJ per pulse. Aerated hollow core fiber (HCF) from a cascade structure, exposed lithium niobate (LN) crystal plates, specially designed chirped periodically polarized lithium niobate crystals (CPPLN) pumped by a 3.9 mm, 3.3 mJ mid-infrared pump pulse.

Pumped by a 3.3mJ 3.9μm mid-infrared femtosecond pulse laser, the HCF-LN system can generate a strong mid-infrared laser pulse of double bandwidth as a secondary FW pump input to CPPLN, which supports efficient broadband HHG processing, further extending the spectral bandwidth to UV-Vis-IR. It is clear that this cascade structure creatively satisfies two prerequisites for the generation of full-spectrum white light: Condition 1, a strongly frequency-doubled pump femtosecond laser, and condition 2, a nonlinear crystal with an extremely high frequency up-conversion bandwidth. In addition, the system involves a large number of synergies between 2nd-NL and 3rd-NL effects.

The synergistic mechanism they have developed provides superior capabilities for constructing UV-Vis-IR global supercontinuum spectra and filling spectral gaps between various HHGS, far exceeding what has been achieved with single-acting 2N-NL or 3rd-NL effects previously employed.

As a result, this cascaded HFC-LN-CPPLN optical module enables previously unachievable levels of strong full-spectrum laser output, not only with great bandwidth (spanning four octave multiplicities), but also with a spectral profile of high flatness (from 300 to 5000 nm, flatness better than 25 dB) and large pulse energy (0.54 mJ per pulse).

"We believe that our proposal is to use the synergy of 2NL-HHG and 3rd-NL SPM effects to create an intense four-octave UV-vision-infrared full-spectrum femtosecond laser source, which is a big step toward building supercontinuous spectral white laser sources with greater bandwidth, energy, higher spectral brightness, and flatter spectral profiles." "This intense full-spectrum femtosecond laser will provide a revolutionary tool for spectroscopy and find potential applications in physics, chemistry, biology, materials science, information technology, industrial processing and environmental monitoring," the scientists said.

Source: Chinese Optical Journal Network
Related Recommendations
  • In depth understanding of the formation of condensation rings in laser spot welding - machine learning and molecular dynamics simulation

    Researchers from the Pacific Northwest National Laboratory and Johns Hopkins University have reported that machine learning and molecular dynamics simulations can help to gain a deeper understanding of the formation of condensation rings in laser spot welding. The related paper titled 'Machine learning and molecular dynamics simulations aided insights into conditioned ring formation in laser spot ...

    2024-12-21
    See translation
  • Diamond Light Source and NPL reach a new five-year agreement

    Recently, two leading UK scientific institutions, Diamond Light Source and National Physical Laboratory (NPL), have reached a new five-year agreement to promote joint collaborative efforts.The agreement was approved by signing a Memorandum of Understanding (MoU), which will bring these two institutions together.Diamond Light Source is a national synchrotron facility in the UK known for generating ...

    2024-04-25
    See translation
  • Redefining the Future of Sensing: In depth Study of Novel Plasma Waveguide Structures

    Imagine in such a world, the detection of trace substances is not only fast, but also incredibly accurate, indicating a new era of technological progress in health, safety, and environmental monitoring. Due to pioneering research on plasma waveguide structures, this vision is becoming increasingly realistic, aimed at enhancing refractive index sensing and spectral filtering. This innovative method...

    2024-03-04
    See translation
  • The application of laser technology in the automated production line of energy storage/power battery PACK

    Lithium batteries are highly favored in the fields of 3C digital and new energy vehicles due to their high energy density, environmental characteristics, and fast charging and discharging. Welding, as a crucial link in the manufacturing process of lithium batteries, has a decisive impact on battery performance and quality. Laser welding technology is increasingly playing an important role in the l...

    2023-12-18
    See translation
  • LOTMAXX Announces the Launch of a Multifunctional 3D Printer with Laser Cutting Function

    LOTMAXX has announced the launch of the ET model, a new type of 3D printer that can also be used as a laser cutting machine. According to the manufacturer, the core component is a fast direct extruder with a printing speed of up to 500 millimeters per second.LOTMAXX ET features an all metal casing with a printing volume of 250 x 250 x 265 mm. According to the announcement, as a special feature, th...

    2023-11-09
    See translation