In the history of human science and technology, the birth of laser technology can be called a revolution in the interaction between light and matter. From Einstein proposing the theory of stimulated radiation in 1917 to Maiman developing the first ruby laser in 1960, this technology penetrated into various fields such as industry, medical care, communications, and military in just half a century, becoming the core driving force for the development of modern society. As an iconic technology in the field of optoelectronics, lasers not only redefine the application boundaries of "light", but also show unlimited potential in cutting-edge fields such as intelligent manufacturing, life sciences, and space exploration.
PART 01
The nature of laser
The essence of laser is light amplification of stimulated radiation (LASER). Based on Einstein's quantum theory, through the synergistic effect of activated media (such as gas, crystal), pump source (energy injection) and optical resonant cavity, the particle number is reversed and amplified. Fixed photons form a highly coherent (phase, frequency, and direction consistent), extremely monochromatic (narrow spectrum), excellent directivity (small divergence angle), and extremely bright beam, providing core light source support for modern technology such as communications, manufacturing, medical and other fields. The nature of laser makes it the only light source that can meet the requirements of high precision, high energy and high controllability at the same time. It provides the physical foundation for optical fiber communication (optical carrier), precision manufacturing (light knife), medical surgery (non-invasive treatment), quantum technology (single photon source) and gravitational wave detection (interferometer), etc., completely changing the modern technology and industrial structure.
PART 02
Application of laser in communication field
The core advantage of laser technology lies in its "four high" characteristics: high directivity (the beam divergence angle is only milliradians), high monochromaticity (the wavelength purity reaches 10^-6 nanometers), high brightness (tens of billions of times the brightness of sunlight), and high coherence (the perfect unity of spatial and temporal coherence). These characteristics have led to the emergence of three major technical branches in the field of optoelectronics.
The first is information optoelectronics, the "light speed channel" for data torrent, the second is bio-optoelectronics: the "antenna of light" of life sciences, and the third is energy optoelectronics: the "blade of light" for precise control. Below we mainly introduce this precision-made "light knife".
As an energy carrier, laser can achieve micron-level precision material processing. In industrial manufacturing, it subverts the traditional mechanical processing model with its advantages such as non-contact processing and small heat-affected zone. And it is more adaptable to the higher requirements of new materials for precision manufacturing.
PART 03
Advantages of laser processing
Laser "light knife" is reshaping the manufacturing paradigm of modern industry with its advantages of high precision, high efficiency and high adaptability:
In the processing of super-hard materials, the laser directly melts or vaporizes the material by focusing a high-energy-density beam (spot diameter can be as small as 10 μm), achieving non-contact processing and avoiding cracks or deformation caused by mechanical stress. In the processing of new materials, when facing brittle materials, traditional mechanical processing can easily cause micro cracks. Laser cutting can control the laser power density by controlling the laser power density(104-10°W/cm²) and scanning speed (20-80mm/s), achieving chip-free cutting with aperture accuracy of ±2μm.
For laser processing of semiconductor materials (such as silicon wafers), femtosecond laser is used to form a modified layer inside the wafer, and the bonding chemical etching enables chip-free cutting with kerf loss as low as 5μm, supporting the miniaturization development of integrated circuits.
