Question 1: What is the difference between a semiconductor laser and a semiconductor pumped laser? What does pumping in laser mean? Semiconductor laser is a laser with semiconductor material as its working substance (i.e. luminescent substance). The so-called pumping is a necessary condition for all lasers to work. No matter what kind of laser it is, it needs a pump. The function of pump is to make the working medium in laser form the inversion of particle arrangement number (this is the condition for forming laser). The semiconductor pump laser uses the semiconductor laser itself as the exciter of the pump. Semiconductor pumped solid-state lasers, of course, use semiconductor lasers as pumps for other solid-state lasers. Is this the simplest explanation I can do?

Question 2: What does flash pumping mean? Does that laser have a pulse output? Flash lamp pumping is a kind of pumping mode relative to semiconductor pumping, and its laser output can be pulsed or continuous, which is mainly realized by power supply driving.

Problem 3: Advantages of semiconductor-pumped solid-state laser 1, low power consumption: the conversion efficiency of traditional lamp-pumped laser is only about 3%, and most of the energy emitted by pump light is converted into heat energy, resulting in great energy waste. The diode used in the semiconductor pumped solid-state laser emits a fixed laser with a wavelength of 808nm, which is absorbed by the laser crystal, and the optical-optical conversion efficiency can reach more than 40%, which greatly reduces the operating cost. 2. Reliable performance and long service life: the service life of laser diode is much longer than that of flash lamp, reaching more than 15000 hours, and the service life of flash lamp is only 300- 1000 hours. The pumping energy stability of laser semiconductor is good, one energy level better than that of flash lamp pumping, and its performance is reliable, so it can be made into fully solidified devices. Long service life, it is the only maintenance-free laser so far, especially suitable for large production lines. 3. Good output beam quality: Due to the high conversion efficiency of the semiconductor pumped laser, the thermal lens effect of the laser working medium is reduced, the output beam quality of the laser is greatly improved, and the laser beam quality is close to the theoretical limit.

Question 4: Introduction of semiconductor pumped solid-state laser Semiconductor pumped solid-state laser is a new type of laser with the fastest development and the widest application in the world in recent years.

Question 5: What are spectral matching and mode matching in semiconductor pumped solid-state lasers? It means that the spectrum of pump light is consistent with the absorption spectrum of laser medium, for example, the absorption peak of neodymium-doped medium is about 808nm.

Mode matching means that the size of the shaped pump spot is close to the size of the fundamental mode oscillation spot of the laser resonator.

Question 6: What is the labeling problem of textile exports in customs declaration materials? Textile export license in customs declaration teaching materials;

1. Scope of application: When exporting textiles and clothing to the United States involves two or more countries (regions), if the origin of the products cannot be accurately determined according to the rules of origin of textiles and clothing in the United States, the enterprise must apply to the United States Customs for binding determination in advance, and the exported products are allowed to be marked as "Made in the Country of Origin" ruled by the United States.

2. Other provisions in the customs declaration specifications:-All textiles produced in China (including raw materials processing) are not allowed to indicate the origin of other countries (regions) on labels, lists and packages.

Excuse me, why 1, which says it can be marked, and 2, which says it can't be marked?

Question 7: What is the pumping source of fiber laser? There are many kinds of pumping sources. It is common that semiconductor lasers with pigtails are directly coupled into optical fibers through optical fiber couplers!

Question 8: Working principle of laser pumping 5. There are many kinds of semiconductor pumped solid-state lasers, which can be continuous, pulsed, Q-switched, or nonlinear conversion such as frequency doubling and frequency mixing. The shape of the working substance is cylindrical and plate-shaped. Different kinds of lasers have different working principles. The following mainly introduces two kinds of end-pumped solid-state lasers and side-pumped solid-state lasers.

The biggest advantage of 1. end-pumped solid-state laser is that it is easy to obtain good beam quality and can realize high brightness solid-state laser. The efficiency of end pumping is higher. This is because, under the condition that the pump laser mode is not too bad, the pump light can be coupled into the working substance through the converging optical system, and the coupling loss is small; On the other hand, the pump light also has a certain mode, and the mode of the generated oscillating light is closely related to the pump light mode, so the matching effect is good, so the working medium has a high utilization rate of the pump light.

It is precisely because of the advantages of high efficiency, good mode matching and good wavelength matching that the end-pumped mode has developed rapidly in the world in recent years and has become one of the key development directions of laser science. It is widely used in laser marking, laser micromachining, laser printing, laser display technology, laser medicine and scientific research, and has great market potential.

2. Side-pumped solid-state laser The laser head of the side-pumped solid-state laser is a pump source consisting of three diode pump modules in a circle, and each pump module consists of three diode linear arrays with microlenses. The average output power of each linear array is 20W, and the output wavelength is 808nm. The device skillfully designs the pump cavity and refrigeration channel by using the glass tube. Most of the surface of the glass tube is coated with 808nm high reflection film, and the rest is coated with three 80 nm antireflection films at 120 to form a pump cavity. The light emitted by the semiconductor pump source is converged to three long and narrow areas coated with antireflection films through three pairs of beam shaping lenses, and then absorbed by the crystal through the glass tube wall. Because most areas of the glass tube are coated with highly reflective films, the pump light will be reflected back and forth in the pump cavity until it is completely absorbed by the crystal, forming a uniform gain distribution on the cross section of the crystal.