The core principle of the pulsed laser epitaxy preparation system is based on the interaction between laser and material, as well as the ordered deposition of thin films. The system mainly consists of a pulse laser, a vacuum chamber, a target material, a substrate heater, and a monitoring module. During operation, high-energy density pulsed lasers (usually ultraviolet or deep ultraviolet lasers) are focused on the surface of the target material, instantly heating the target material locally to temperatures of thousands of degrees Celsius or even higher, causing atoms, ions, or molecules of the target material to be excited and detached from the surface, forming a plasma "plume" containing multiple particles. In a vacuum environment or a specific gas atmosphere, these high-energy particles move along a straight line towards the heated single crystal substrate. With the lattice template and energy conditions provided by the substrate, they are arranged in an orderly manner according to the crystal structure of the substrate, and finally deposited to form a single crystal thin film that matches the substrate lattice. Throughout the entire process, the pulse width, energy density, repetition rate, substrate temperature, cavity pressure, and other parameters of the laser can be precisely controlled, providing flexible space for optimizing the structure and performance of the thin film.

In the growth of single crystal thin films, the pulsed laser epitaxy preparation system exhibits significant advantages. Firstly, precise control of ingredients. The high-energy characteristics of lasers can achieve the evaporation of almost all solid materials, and the composition of the target material can be completely transferred to the thin film, effectively avoiding the problem of component deviation that is prone to occur in traditional sputtering techniques. It is particularly suitable for the preparation of multi-component single crystal thin films (such as oxides, nitrides, etc.), ensuring the accuracy of the chemical stoichiometry of the thin film.

Secondly, the crystal quality is excellent. The particles in plasma plumes have high kinetic energy and can obtain sufficient diffusion energy when deposited on the substrate surface, promoting the ordered arrangement of atoms and reducing lattice defects. At the same time, precise control of substrate temperature and lattice matching design enable a good epitaxial relationship between the film and substrate, significantly improving the crystalline integrity and electrical and optical properties of single crystal films.

Thirdly, the growth process is controllable. By adjusting laser parameters, substrate temperature, and cavity environment, precise control of film growth rate and thickness can be achieved, and even atomic level flat ultra-thin films can be prepared. In addition, this technology also supports the epitaxial growth of heterostructures, providing the possibility for the preparation of new devices such as high-temperature superconducting devices and quantum devices.

Fourthly, it has broad compatibility. Pulsed laser epitaxy can be applied to target materials and substrates of various materials, whether they are metals, semiconductors, or insulators. Corresponding single crystal thin films can be prepared through this technology, and the damage to the substrate during the growth process is minimal, further expanding its application scenarios.