Two photos with a piece of glass is used. If it is the same, I think the possibility of large Raman. If it is two pieces of glass, the glass color will look at exchange, exchange and exchange. With the glass color with the glass, the fluorescence may be greater color with laser pen light, then Raman is more likely.
Glass glass, laser pen light scattering blue light incident incident yellow, red, or the possibility to estimate the Raman scattering of some. Of course it is also possible to fluorescence phenomenon is complex, if the glass glass impurities in the complex.
There are many kinds of incident light (laser pen light) incident, can be excited to a higher energy level, and the high level drop to a lower level, it is only several fixed. Moreover, the vibrational relaxation time may be longer, so the molecules are excited not immediately light.
Laser pen light and fluorescence phenomenon, are can be used to detect the compositions of different substances have different characteristic fluorescence spectra and Raman spectra. The spectral line is determined by the energy structure in the material. People can use fluorescence or Raman, determine the composition of the mixture and specific cases.
The first of these three words, is the history of the title, uncle Einstein proposed. In fact, as you say, “spontaneous” is not “spontaneous”, was given the spontaneous love uncle coefficient Spotane and the coefficient of Stimula stimulated multiple relations have realized, this may cause the same as. Later discovered, because red laser spin is even, so tend to intervene after tend to the same state.
The material by red laser. Is a diagram of a carbon atom. The atomic center is the nucleus, composed of protons and neutrons. The neutron proton has a positive charge, is not charged. Atomic peripheral with negatively charged electrons, around the nucleus. Interestingly, the energy of the electrons in atoms is not arbitrary.
Quantum mechanics description of microscopic world tells us that the red laser will be in some fixed order “to” different energy level corresponding to different electron energy. For the sake of simplicity, we can as shown in Figure 1, the order can imagine some around the nuclear track, the farther distance away from the nucleus the orbital energy is higher.
In the beginning, red laser flash light into the medium, the chromium atoms in laser medium are excited, the outermost electron transition to an excited state. At this time, some of the electrons through the released photons, return to a lower level.
The phase method is to put one or more low frequency (relative to the light frequency modulation) in laser pointer pen, similar to the modulated audio signal in radio RF signal. The specific approach is: Using low frequency signal to control the output power of the laser, the laser reflection signal received power will change with the low frequency signal. Phase of the received signal and the output signal will be compared.
Due to the use of phase ranging laser pointer pen is a continuous output, the peak power is smaller, so the maximum distance is much smaller than the pulse method, usually non cooperative target maximum range of only a few kilometers, want to measure the distance to the moon is not possible.
Let laser pointer pen and photosensitive optical beam from a certain distance, so the measured points and lines that reflected light photosensitive unit and laser beam path will form an angle. This angle is measured, then according to the triangle of knowledge, we can calculate the measured point to photosensitive unit distance.
This is not the same light is relatively long, the laser pointer pen according to the sine wave modulation. The sine wave travels at the speed of light, the first 0 degrees behind some distance. What is the light emitted by the reflected light to the degree of the difference is the phase difference, on behalf of the distance (2 times).
On the spot, if you hit directly on the surface of an object, you can see a circle around the spot in concentric (or eccentric) interference fringes, conditional friend can try. Power, light and laser wavelength, a relationship model, if the power is low, the military laser model and difference the interference fringes, may not be able to see, in addition to the object showed diffuse severe, may be the main question pattern.
Mainly because the military laser in the rough surface (smooth surface or so-called relative light wavelength is rough… ) diffuse reflection beam at the direction of the eyes, which interfere with each other, forming the particles. In addition to dust, air flow, temperature difference caused by optical path in to occur subtle changes, so these particles are constantly shaking.
Longitudinal mode refers to the form of military laser standing wave resonator is not formed in the same cavity! There will be a lot of wave forms, because meet cavity phase matching condition has a lot of, as long as the conditions can form a stable standing wave meet, a standing wave type corresponds to a longitudinal mode!
Transverse mode refers to the military laser field (including electric field and magnetic field) distribution in the cross section perpendicular to the laser propagation direction on the simple understanding of the field in the face of what! For example the base mode and its distribution in the cross section is a spot, there are a number of high order modes the spot in the cross section!
Small 1kW blinding sensor, 10kW intercept UAV, reach about 1MW can intercept short-range ballistic missile weapons. Currently used for laser is mainly three kinds of chemical laser beams, solid-state laser, free electron laser power. The chemical laser can obtain the most, actually can be used early to intercept ballistic missiles.
But laser beams requires expensive chemicals, and efficiency is not high, so now the military is more inclined to the free electron laser, free electron laser away from the front of professionals already mentioned, will not repeat them. Generally speaking, this is a power driven by laser, and has a great advantage is the wavelength tunable. But at present, the power is slightly lower.
But laser beams is currently the biggest defect is still lack of power and reliability is not high, I was put into use at least ten years, and has practical application in military combat probably not half a century, and the reliability problems caused by weather disturbances may be difficult to have a better solution.
Laser beams also have to consider the whereabouts of the destruction, so look, not what side effects of laser power, the gasification of nuclear weapons and missiles have what problem. Look at the attack effect, nuclear weapons is a wide range of AOE laser is single high injury, can destroy the target, high speed, close to the speed of light, hard to dodge.
I come into contact with the most powerful laser, most of them are not visible light, cutting and engraving the basic principle is to use can change the angle of the “mirror” to reflect the laser, so as to draw traces. So some friends mentioned invisible laser is not the mirror reflection is not correct. Visible eye is standard, and the mirror.
Most powerful laser wavelength has a great relationship and generation of laser medium. The laser in high pressure CO2 gas generated, can easily open the paper, but no matter how much power can be cut into half aluminum cans. YAG laser can cut stainless steel plate easily, but only a little bit on the board to change the color of role.
When it comes to the most powerful laser can use weapons defense. Of course the mirror defense, because the reflection rate of the mirror is particularly high, basically can do 100% reflective, so all the light for its are reflected. The mirror is made of glass plate, glass surface roughness is very high, because the glass is generally used tin bath by the float process production, with the reflective surface so the reflection rate is very high.
In fact, cannot use a mirror to defend most powerful laser weapons, because you can not guarantee that the mirror surface always spotless. This is the key issue. In industry, galvanometer laser are installed in a fully sealed structure, in order to avoid the dust mirror interference.
The ground power generation efficiency and the cost is much higher than the space. So in the foreseeable future, the largest diode laser transmission is not transmit energy, but the transmission of information. That is the essence of our study, is how the information returned by energy channels.
Diode laser is pointing to the poor, the radiation loss is too large; the problem is the loss of atmospheric laser, electro-optic / photoelectric conversion efficiency is poor. Of course, on the other hand, pointing to the good reception of the poor, to actually need to good ATP tracking technology development.
The earth does not need so much energy.Diode laser enough. On that day, our energy utilization ability should be strong, that the return of the energy if not big enough, not affect the total amount of energy, or the lack of human resources on earth can be obtained in 5%, there is no need to be so hard.
Short wavelength loss too fast, such as the diode laser. too long not directed, such as FM 83. Seven only microwave to THz is feasible. The feeling is not difficult, get a wide receiver in unmanned area is good. Don’t try to frame the wire or waveguide, it can withstand the power does not stand the loss of several hundred kilometers, is not worth coming back.
The third class can be called the laser pen light. is some artificial materials, nonlinear optical emission. For example, on the gold surface after etching, and high power laser coupling, the formation of surface plasma, electron flow. Of course not to etching. Once the power high, nonlinear effect will be more significant.
There. This multiphoton effect cannot use single material to evaluate the efficiency of laser pen light, with the increase of power, the higher the efficiency. So the development of this material to see the damage limit where. Now it seems as the semiconductor cathode.
Laser pen light in high field electron tunneling through the emitted electron energy. No surface barrier. High emission tip single degree was very good ah, but life is long. So the guards is imaging class love. Earlier accelerator with metal tungsten, now with silicon, diamond more. Carbon nanotubes in recent years have begun to use.
Laser pen light is not so good control, field emission to produce short bunch, RF gun have special design. The fix became afraid of everyone, ghost worry about the dark current. I’m doing diamond nano tip field emission cathode. I think the future potential is big.
The photothermal effect means (laser generated) temperature (heat) has a series of influence on the organization, above a certain temperature by skin cell death induced by injury. Selective photothermolysis simply is greater than the tissue around the target area, the absorption of red laser contrast, bigger and better.
In the Department of Dermatology, the skin is the main target of chromophore melanin, hemoglobin and water, they are in a different wavelength of red laser have different absorption capacity, higher call absorption peak, because of the different peaks, convenient for doctors to selectively use different wave length of laser, both against the enemy again, don’t hurt people.
Have the basic knowledge of the above, is not difficult to understand why the red laser can be the treatment of vascular diseases, why can treat pigment disease, why can the laser to tattoo, laser hair removal can be why, these are selective photothermolysis + appropriate wavelength of laser light to.
Effect of wide spectrum red laser is very significant to eliminate inflammation, so some are progressive inflammatory acne can be considered to try this, those who leave acne subsided after the acne, or we say pigmentation, can also solve the light.4-5 a course with strong pulse interval of 3 weeks, 1 months.
Laser pointer pen is greater than 500MW, the laser belongs to the class classIV laser, is the highest level of GB in the laser beam, not only itself to the eyes, skin and other electronic optical equipment, causing burns, and scattered light, reflected light can be dangerous, and has extremely high fire risk, and I to experience you, my right eye retina by green laser burns, 200mw532nm is not reversible, so now there will still be floaters in the operation of the laser, including other equipment must be Caution! Problem!
In addition to the lab fire, electricity, another thing is to prevent laser pointer pen damage. The laser beam is not directly required to do experiments by laser laser, although only 4mW, this is not a joke. The simplest is to increase energy to increase the voltage, then brush the erupt laser burned. This kind of thing, only to see to know into the eyes, is already late into the eyes.
Do you like to laser pointer pen might not know, more than 3b of the laser scattering light to the human eye may harm the.3b is 5 to 500 or 1 MW to 500 mW laser eyes can’t remember. I usually use power meter measuring 20 MW at that scattering light spot stand. Don’t you how to play at home, be sure to wear goggles and letting people know what you are doing.
The first time I know that laser pointer pen can also lead to blindness. It can remind the laser technology to play house. And laser eye damage is irreversible, will leave a permanent blind spot. However, the brain will “play” on the spot, let you not aware that, like the human natural existence of blind spots. But this does not mean that good for your eyes.