The principle and application of laser

The principle and application of laser

Laser is another major invention in the 20th century after nuclear energy, semiconductors, and computers. It is widely used in industrial manufacturing, biomedical and other fields due to its good monochromaticity, directionality, brightness and other characteristics. The most accurate knife, the most accurate ruler, and the brightest light. Since the invention of laser technology, the global laser industry has developed rapidly, and laser technology has become one of the important supporting technologies in many fields.

So, what is a laser? Next, Weike.com will give you a detailed introduction.

generation of laser

Laser, also known as "laser", its full name is "stimulated radiation optical amplification". In 1917, Einstein proposed the "stimulated emission" theory, a photon causes the excited atom to emit an identical photon basis. In 1960, Maiman, a researcher at the Hughes Aeronautical Laboratory in California, USA, invented the world's first ruby laser. In 1961, China's first laser was born in Changchun Institute of Optics and Mechanics led by Wang Daheng. In 1965 Bell Labs invented the first YAG (solid-state) laser.

The particles in the atoms of some substances are excited by light or electricity, and they transition from atoms of low energy level to atoms of high energy level. Light with exactly the same phase, frequency, direction, etc., is called laser light. When the pump light is irradiated, the ground-state ions absorb light of a specific wavelength and transition to the E3 energy level, and then rapidly transition to the E2 energy level through a non-radiative transition, where more ions can be aggregated. When the external pump is strong enough, a population inversion will be formed between the E2 energy level and the E1 energy level, that is, the number of ions on the E2 energy level is more than that of the E1 energy level. After the population inversion is realized, each external photon with energy hν will excite an atom on the E2 energy level to make it transition to the ground state, and at the same time release a photon with energy hν, the total energy of the photon is continuously multiplied, thus realizing Stimulated emission amplification (gain) process.

what is a laser

A laser is a laser generating device, which is mainly composed of a pump source, a gain medium, and a resonant cavity. The pump source is the excitation source of the laser, and the resonant cavity is the circuit between the pump light source and the gain medium, and the gain medium refers to the working substance that can amplify the light. In the working state, the gain medium absorbs the energy provided by the pump source, and outputs laser light through the resonator oscillation mode selection.

Laser is the core component of laser processing equipment, and plays a pivotal role in the cost structure of laser processing equipment. Lasers can be divided into many types according to the working substance, output band and output type.

Lasers can be divided into solid lasers (ruby Al2O3, yttrium aluminum garnet lasers), liquid lasers (dye lasers), gas lasers (helium-neon lasers, argon-ion lasers, etc.), semiconductor lasers, fiber lasers, and free electron lasers. According to the output band, lasers can be divided into far-infrared lasers, mid-infrared lasers, near-infrared lasers, visible lasers, near-ultraviolet lasers, and vacuum ultraviolet lasers. According to the output type, it can be divided into: continuous wave laser, quasi-continuous laser, short pulse laser, ultrashort pulse laser.

Development and Application of Laser Technology

As one of the advanced technologies in modern manufacturing, laser technology has the advantages of high precision, high efficiency, low energy consumption and low cost that traditional processing methods do not have. The large selection space can better solve the technical problems in processing and refining caused by different materials. With the continuous development of laser technology and laser micromachining application technology, laser processing technology can replace traditional machining in more fields, while laser fine micromachining has higher precision, stronger flexibility, smaller thermal effect and wider application. It has gradually become the core processing technology in the high-end manufacturing field.

In terms of laser applications, laser technology can be widely used in cutting, welding, drilling, marking, engraving, measurement, diagnosis and other fields. my country's industrial upgrading is already on the line, in micro welding, precision measurement, biomedical diagnosis, chip manufacturing. The demand for laser technology in many fields is constantly rising, and laser technology has entered a new process of rapid development.

From the perspective of the development of the laser industry, laser technology has been widely used in consumer electronics, 3D printing, semiconductors, new energy, display, biomedical, laser detection and other fields. Many domestic companies have already competed with foreign companies. Its strength and influence in the international laser industry are also getting stronger and stronger.

All in all, laser has played a vital and irreplaceable role in some fields, and more and more industries have begun to pay attention to the application of laser technology, which makes domestic laser industry companies continue to strengthen their investment in the field of laser technology research and development. , The competition in the laser industry is becoming more and more fierce. For the development of my country's laser industry, this is undoubtedly a positive signal. In this context, we can narrow the gap with international counterparts faster, fill our own technological vacancies, and provide important technologies for the development of my country's science and technology. support.