English

Progress in Laser Physics: Reducing Residual Amplitude Modulation for Accurate Measurement

1157
2024-03-18 13:56:19
See translation

Driven by the pioneering work of scientists such as John Young Hall, significant progress has been made in precision measurement in the field of laser physics. His contribution to laser frequency stability and precise measurement using lasers has led to groundbreaking techniques that significantly reduce residual amplitude modulation.

John Hall's research focuses on understanding and manipulating stable lasers, laying the technical foundation for measuring small fractional distance changes caused by gravitational waves passing through them. This work on laser arrays earned him the 2005 Nobel Prize in Physics.

On this basis, JILA and NIST academicians Jun Ye and their team embarked on an ambitious journey to expand the boundaries of precision measurement. They focus on improving the Pound Reverse Hall (PDH) method, a specialized technique developed by RV Pound, Ronald Drever, and Jan Hall, which plays a crucial role in precision optical interferometry and laser frequency stability.

Although the PDH method is crucial for ensuring laser frequency stability, the limitations of residual amplitude modulation (RAM) may affect measurement accuracy. In a recent paper published in Optica, Ye's team, along with JILA electronics staff Ivan Ryger and Hall, proposed a new PDH method. This method reduces RAM to an unprecedented low level, simplifies the system, and enhances robustness.

PDH technology is the foundation of various experiments, from gravitational wave interferometers to optical clocks. Further improvement of this technology can bring progress to many scientific fields.

The PDH method was introduced in 1983 and has become the cornerstone of laser physics, widely used in various experiments. It precisely measures laser frequency or phase fluctuations by introducing special "sidebands" around the main beam (referred to as the "carrier"). Comparing these sidebands with the main carrier helps detect subtle changes in frequency or phase relative to the reference, thereby reducing noise and errors.

Physicists use this technique to detect different environments, such as optical cavities made of mirrors, by "locking" the laser into the cavity. However, noise like RAM can alter the relative offset of the reference beam, thereby affecting stability.

Reducing RAM is crucial for improving the stability of PDH technology and laser measurement. The new method developed by JILA researchers is expected to simplify this task and make significant progress in precision measurement and laser physics.

Source: Laser Net

Related Recommendations
  • Implementing and studying non Hermitian topological physics using mode-locked lasers

    A mode-locked laser is an advanced laser that can generate very short optical pulses with durations ranging from femtoseconds to picoseconds. These lasers are widely used for studying ultrafast and nonlinear optical phenomena, but they have also been proven to be applicable to various technological applications.Researchers at the California Institute of Technology have recently been exploring the ...

    2024-03-27
    See translation
  • UK to Build World's Largest Power Laser: Accelerating the Use of Nuclear Fusion and Promising to Obtain Clean Energy

    According to reports, British scientists will build the world's largest power laser. They hope that this £ 85 million (approximately $103 million) device can accelerate the use of nuclear fusion and potentially obtain clean energy, which is inexhaustible.According to the report, the "Vulcan" 20-20 laser will be built in Havel, Oxfordshire, and it will produce a laser brightness that is 24 t...

    2023-10-09
    See translation
  • The new progress of deep ultraviolet laser technology is expected to change countless applications in science and industry

    Researchers have developed a 60 milliwatt solid-state DUV laser with a wavelength of 193 nanometers using LBO crystals, setting a new benchmark for efficiency values.In the fields of science and technology, utilizing coherent light sources in deep ultraviolet (DUV) regions is of great significance for various applications such as lithography, defect detection, metrology, and spectroscopy. Traditio...

    2024-04-10
    See translation
  • Trumpf Laser releases latest fiscal year data

    Recently, German laser giant Trumpf released data for the fiscal year 2023/24. The latest financial report shows that the group's sales decreased by 4% and order volume decreased by 10% in the fiscal year 2023/24.Despite these setbacks, Germany has become the company's strongest single market for the first time in many years, highlighting a shift in market dynamics.At the end of this fiscal year, ...

    2024-07-19
    See translation
  • Shanghai Optical Machinery Institute has made progress for the first time in hard X-ray zoom beam imaging

    Recently, the High Power Laser Physics Joint Laboratory of Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, completed the research of hard X-ray zoom beam splitting imaging on the micro focus X-ray source for the first time, and solved the problem of beam splitter limitation in the hard X-ray band. The related achievements are titled "Bifocal photo scene imaging in the...

    2024-04-08
    See translation