English

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

1212
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
  • Which automotive parts can use laser soldering technology

    Laser soldering is widely used in the manufacturing of automotive parts. Here are some common automotive parts that can be welded using laser soldering:Automotive electronic control systemEngine Control Unit (ECU): The engine control unit is the "brain" of the car engine, which receives signals from various sensors and controls the operation of the engine based on these signals. Laser soldering ca...

    02-10
    See translation
  • An innovative technology that can make light "bend"

    A research team from the University of Glasgow in the UK drew inspiration from the phenomenon of clouds scattering sunlight and developed an innovative technology that can effectively guide or even "bend" light. This technology is expected to achieve significant breakthroughs in fields such as medical imaging, cooling systems, and even nuclear reactors. The relevant research results were published...

    2024-11-11
    See translation
  • The technological iteration route of automotive millimeter wave radar chips

    The rapid development of intelligent cars and autonomous driving technology has made millimeter wave radar inconspicuous, and the widespread application of millimeter wave radar has driven the technological evolution of MMIC.From the expensive gallium arsenide (GaAs) process in the early days to the mainstream CMOS and SiGe processes today, and then to the future promising FD-SOI process, the cont...

    2024-12-07
    See translation
  • Korean laser company AP Systems establishes new AVP equipment division

    Recently, AP Systems, a well-known laser manufacturer in South Korea, established a new AVP equipment division for the advanced packaging field. This business unit will focus on laser equipment required for advanced packaging processes of high bandwidth memory (HBM).AP Systems is a subsidiary of APS Group, mainly focused on the fields of display and semiconductor laser processing equipment. It foc...

    01-15
    See translation
  • The researchers used ultrafast lasers to create nanoscale photonic crystals

    The optical properties of photonic crystals are closely related to their lattice constants, which are usually required to be in the same order of magnitude as the operating wavelength. In a crystal material, the photonic crystal structure is formed by the periodic arrangement in space of units whose dielectric constant is different from that of the crystal itself, and whose lattice constant depend...

    2023-08-04
    See translation