Laser technology pioneer ---Townes
Townes, in 1915 the United States was born in Greenville, North Carolina. On the 16-year-old university student in physics and linguistics, 24 years old to obtain a doctorate in physics. Townes of almost every kind of events of interest to all, he is a Da Vinci-like figure - a versatile scientist. In addition to his well-known physicist and professor, is also a swimming athletes, travel, home orchid cultivation and linguistics master's degree, he was teaching the choir singer, and former Columbia University in the vicinity of a church deacon. Townes on a society, we run into the Second World War. At that time, the country as a whole have a very busy time for war service. Townes young bent on engaging in theoretical physics research, but can not find appropriate work. Finally, he had to enter an electrical company, when a radar engineer. Radar engineer is the responsibility of the overall structure of the radar research and design process, rather than pure research. However, the Townes and can not be buried; war radar, and the manufacture of advanced radar need a solid knowledge of microwave electronics. Townes then began to study carefully the microwave electronics. Soon he became an versed in microwave electronics expert, invented the first microwave laser. Success is a failed experiment began.
     World War I, slower aircraft, the engines sound audio. Air defense forces by the ear to listen to the sound of aircraft to determine whether enemy invasion. At the beginning, the special hearing sensitive monitor for the blind. Later, using loudspeakers fitted with the listening device to detect the enemy to come and go. During the Second World War, the aircraft has greatly enhanced the speed of flight, reaching almost half the speed of sound. Listen to the voice of the methods used to detect enemy is much too slow, and often heard the roar of aircraft motors, the enemy is coming to a head over. As a result, scientists have focused on countries to step up research to create just at the time of the birth of electronic air defense equipment - radar. Radar is the core of the microwave oscillator, which have a very high frequency electromagnetic waves through the launch of the radar antenna out and fired at the target; goal to reach the surface, it's part of the reflection of electromagnetic waves to come back, the radar receiver to receive, in the screen To show the direction and target distance. Electromagnetic transmission speed of 300,000 kilometers per second, the plane was more than a few hundred kilometers per hour, I do not know how many times faster, which found that aircraft as soon as possible to meet the requirements; listening on the other aircraft to determine the location is very accurate, Know that the only aircraft in a position of a few dozen times about the scope. Radar can only several errors in the accuracy of determination of the specific location of the aircraft. The warring countries would like to make their own radar performance over each other's radar, in order to be able to deal more effectively with the invading aircraft, so do everything possible to develop a new type of radar. One way to improve the radar's frequency rising. At that time, as has been the emergence of the other party can interfere with radar anti-radar equipment. For example, a group of flying the plane, which left the aircraft fleet is far above the other containing a radar station to launch strong electromagnetic equipment. This strong electromagnetic signals in each other's radar screen the reflection of the fleet to cover up the weak electromagnetic signals to live, so that the radar into a "blind", the group will be able to quietly slipped over the other side, a cover-up of modern electronics. In order to deal with such interference, we should be looking for ways to own the frequency of electromagnetic waves emitted by radar and other electromagnetic interference is not the same frequency, and radar receivers on the electromagnetic waves emitted by itself, has high sensitivity, so that does not work on the other side of the interference . As a result, need to look at a new frequency electromagnetic waves.
At that time, the design of the new radar, are doing a very high frequency, reaching a 10 Hz, 3 cm wavelength. Proof of the theory: the shorter the wavelength, the beam will be fired out fine, found the target to determine its location will be able to improve the accuracy. Moreover, the higher the frequency, antennas can be made more small, the use of the field, it installed in the vehicles, mobility and flexibility to improve a lot.

In order to further improve the radar's frequency, the Air Force to study Townes 1.25 centimeter wavelength radar, radar technology to open up new areas of the use of the new radar manufacturing of precision bombing targeting equipment. Townes forecast such a short wavelength of electromagnetic waves to be in the air to absorb water vapor out, can not be used for radar. The results of the tests to prove that he's predictable is right.
However, Townes did not stop there, but to turn to the study of water vapor absorbed waves. In the study, he found that ammonia absorption with a series of phenomena such as electromagnetic waves, which created a new physics - microwave spectroscopy, which is an open secret in the world of micro-key. Soon he was hired at Columbia University physics professor.
As a professor, he did not stop their research, but focused on how to have a millimeter wave, sub-millimeter wave on the issue. This is a science and technology was a major problem, no one can resolve, a strong thirst for knowledge led him to the science and technology into new areas.
At that time, have a high frequency, the length of the electromagnetic wave, such as centimeter wave, the use of the metal as a resonator oscillator; have a wavelength shorter than cm wave of the millimeter wave or sub-millimeter wave, but also to be used than Huochai Geng The small metal box. The box is the most difficult of the wall must be polished very bright and clean, and this is the level of technology at the time of the impossible.
Townes encountered a problem. However, a more difficult challenge has aroused his interest; no way for scientific research, the key is to find a overcome difficulties and solve key problems.
He first from the wavelength of electromagnetic waves also bound to be shorter in the direction of this development point of view: Even if the millimeter wave can have a metal box miraculously processing, then later to produce micro-wave with more detailed smaller box again How should we do? Must be fundamentally have to find a new method of high-frequency electromagnetic waves. An alternative idea in the minds of Townes flash: the use of tiny atomic structure inherent
The millimeter-wave frequencies to produce. This is a bold creative vision. To do next is not only derived from the theory that the feasibility of the idea, but also to experiment with technology to prove it is fully able to do. There is no ready-made test equipment, Townes had to do to take advantage of the experimental microwave equipment, from the molecular study of movement centimeter wave begin to identify themselves on the basis of the principles and methods of the experiment is on the right track in order to further prepare for millimeter wave generated. Early in 1950, the U.S. Navy set up a study by the Department of scientists and engineers composed of members of the
Council to study the sub-millimeter wave and millimeter wave generated.
The spring of 1951, Townes to Washington to participate in the Committee convened its second meeting. While the others sitting around a conference table. Yingxian Chu constantly mentioned his brain thinking of the various formulas and experimental programs. Early one morning, the dawn of Xi Wei, also kept in the earth layer in chiffon. He woke up the next day on the thought of the derivation formula is not yet adequate, early morning is the use of clear-headed good time to re-examine the revision. He dressed in Qingshouqingjiao, out of the hotel, went to the nearby Franklin Park. Spring Park is a charming, the beginning of a long tree leaves, flowers in full bloom with a red Congcong of azaleas, giving the impression that the sound waves birds are particularly quiet in the morning. Townes in a bench to sit down, eyes looking at the beautiful flowers of ecstasy, the brain has been thinking about have a very short wavelengths of the electromagnetic wave formula. A string of figures in the equation Yi Zuzu Townes of like minds, like spring water emerged. Suddenly, he wanted a new method of calculation, in order to work out quickly pocket pen, not just paper, a search of the pocket, only to find a used envelope, they tear the envelope, the envelope in the back of a few Road, just up formula.
He Fenbijishu only a few minutes, even a need to stimulate the number of molecules can be molecular oscillation, as well as the oscillator to allow the value of the loss. At that time, Townes is the calculation of ammonia as a target. He not only in theory be inferred from the ammonia molecules can be stimulated to produce 1.25 cm wavelength of electromagnetic waves, it is envisaged that such oscillations can produce a specific method. Townes did not immediately announce their new discovery, but returned to the laboratory, according to its own new ideas, started trial production maser. He and his colleagues, and graduate student, working a full two years; in the past two years, along with their design, manufacture, testing, demolition, reconstruction, over and over again, but have not been successful. There are two friends urged him to give up this futile and a waste of money the trial, but his unwavering, to continue the trial.
By the end of 1953, Townes was invited to a workshop to make a spectrum of short-term lectures. One day, he flew the students to come, a report on his exciting news: the success of the maser!
Teachers and students came together on the ground floor restaurant, a toast to celebrate the hard-won success. During the meeting, they should think of this new invention from a simple, loud Latin or Greek names. However, the victory of the passion so that they can not calm down for the night they did not find a suitable name. The next day until the evening, they created a satisfaction acronym "Maser" - "Manse" - as the invention of a new device named. It means "maser." Maser after another on the basis of the invention of lasers, according to Townes also look to create a "Laser" the acronym for its name. Only two Yizizhicha. One "aser" is the stimulated emission of the English abbreviation of the word, and the M and L respectively on behalf of the optical and microwave. But it also means that they have a principle is the same, the oscillation frequency, or just not the same wavelength. Found that "Manse", Townes modestly said it was his students and glorious victory; students because he is not a risk when Dr. risks involved in the study to work. In the near future, Townes found that "Manse" There is a strange temper, which have a high frequency electromagnetic waves, and always at a fixed frequency oscillation, in what way can not change it. At that time, Townes is also unable to say such a device lasing what practical value. Later, they would understand, "Manse" generated by microwave energy at a precise frequency oscillations, is the "Manse" advantage rather than disadvantage: Since the number of oscillations per second it is always the same, so as long as the measure The oscillation frequency will be able to know the precise time interval. So, there are people such as a laser-clock time standard, then create the world's most accurate clock, "to the" error of 1 million years, only 1 second. Maser can only have a centimeter wave. Townes is needed is sub-millimeter wave and millimeter wave. However, the millimeter-wave laser-generated but has not made, and no radiation was found to millimeter wave, sub-millimeter-wave material. Townes made a prompt decision to move forward pass, research directly generate visible light laser oscillation.
In 1958, Townes and his collaborators Xiao Luo, after a long period of Thoughts, research, calculation, for the first time put forward the theory of light oscillation condition computing and optical laser design principles, and also the new laser device The use of a forecast made. The article novel idea, detailed argument, assuming a bold, calculated precision, combined with practical measures, immediately won the physics of electronic industry attention. Europe and the United States, many of the laboratory conditions, according to the papers suggested that tests one after another manufacturer.

Extraordinary

Laser described the background, it is necessary to talk about the laser goes on the "character" and "characteristics". As the laser light is only a special light, so we have to start from the light.
People on the light and optical phenomena for observation and study for thousands of years of history in our country at the time of the Spring and Autumn thinker Mo scientific work ", said" there is light on the phenomenon described. Light and human life are closely related to people living in the everyday world of light. But it was not until the beginning of this century, it is the essence of it should have a better understanding.
To calm a stone's throw lake, the water will have a ripple of the circle, which is the most intuitive wave - water. Struck a chord, in the air have heard the voice of the people known as the sound waves. Radio, TV antenna, we can not see a launch, to hear a wave, which is the turn of the changes in the electric and magnetic electromagnetic waves. We just felt, but no one think it is a fluctuation. Modern scientific theory shows that light is also a kind of electromagnetic wave, with the characteristics of waves; only a very short wavelengths of visible light, less than 1 micron, high frequency, 1015 to 103 oscillations per second, so people can not feel it's volatility .
Just atoms, molecules produced by the movement. Changes in molecular and atomic energy, will produce light oscillations. In that case, that energy is how to change the status of it?
The beginning of this century, scientists have for us to draw a picture of the atomic world. It really like our solar system: the sun's position on nuclear is, for many, like e-like planets in their orbit around the operation of the atomic nucleus. Hydrogen is the simplest atom, it is only one e-turn around the atomic nucleus. Electronic near the nucleus of the running track, the less energy; in the atomic nucleus away from the track running, more energy. If the hydrogen atoms of an electronic excitation energy to the great distance of the track, then back to shock it back on track, it will release a photon, which is luminous. To make light-emitting hydrogen atoms, you can power off approach: the thin hydrogen gas into a discharge tube inside. Electricity, electronics from the cathode, the electric field to accelerate, into the anode, e-kinetic energy into electrical energy. Electronic and high-speed collisions of atomic hydrogen, the hydrogen atoms out into electronics. Some electronic energy only to the e-hydrogen atoms to make them less energy from the track, "excited" to go to the track more energy, and energy will be improved. The atomic electron energy increased, the atoms in the excited state, it is unstable, like in a cone steeple on the ball, ready to fall off. When a high-energy excited state of atomic energy back to the low state, in the form of light energy to release. Judging from the current human knowledge has, the light is generated.
Light-emitting atoms is a prerequisite for the outside world must be to stimulate energy. Almost all kinds of energy that can be stimulated into light conditions.
Of course with laser light of the nature, it does not mean that all of the laser light is all. For example, sunlight, candlelight and the lights, which produce light when the atom's internal energy change is chaotic, light colors are different. These light shooting in all directions, "fragmentation", is not observe the "discipline." This "spontaneous emission" of light can be compared to the square of the crowd, taking all of that unrelated. Laser is the atomic, molecular, to a certain way to stimulate arising under the stimulated emission. A team of soldiers like to hear the order, immediately Liecheng tidy team, everyone according to a certain degree of order, space and pace, organized a narrow straight line of long queues started to move forward. Here commander of the order is to stimulate like, a soldier is inspired by the atom, molecule. Maiman laboratory in the world's first injection of the dark red laser beam is from the bottom of the ruby inspired by the atomic. Scientists from the unusual to see a red light in a new physical miracle.

The laser mechanism

Laser is a special kind of electromagnetic waves. The laser is more than 100 years scientists have in-depth study of the phenomenon of electric, magnetic and optical phenomena is the crystallization. Laser direct-founder, can be traced back to the great contemporary scientist Albert Einstein. Einstein won a Nobel Prize. It is interesting to note that he is not winning the world-famous because of the relative theory, but because he was in 1905 put forward by the light quantum hypothesis. According to this hypothesis: just by the large number of photonic components, different colors of light from different components of photon energy. Einstein used this hypothesis to explain the photoelectric effect was astonishing success. In 1916, Einstein "on the quantum theory of radiation" in papers submitted in electronic atoms can be subject to "shock" and giving off photons. This stimulated emission process is to have a basic laser physics.
The laser-nouns from the English word "Laser" the translation. Initially, according to its pronunciation in English, translated as "les" and "laser" and so on, not the justifications for why people read it. Later, it was based on what it means, translated into "stimulated emission light." It is clear that the translation of the meaning clear, and with it the distinction between ordinary light clearly expressed, but too many words, is not convenient to read.
In 1965, China proposed a number of well-known scientists, "stimulated emission light," the acronym "laser" word, so that a relatively simple comes to people's mind. There are two forms of luminescence. Spontaneous emission is a form of luminescence. In addition, there is another form light-emitting, and that is stimulated emission. What is the stimulated emission does? In other words, the original high-energy at the atomic level, but also in other photonic stimulation or induction, the transition to a low energy level and at the same time launch a similar photon energy. As a result of this process is stimulated by external photons, so called stimulated emission. Interestingly, emerging with the photon with exactly the same as the outside photonic state, that is, frequency, wavelength, the same direction. As long time have stimulated emission, will be able to make a photon into two photons, and the two-photon
Give rise to other atoms occur stimulated emission, then, within a very short moment in order to stimulate the number of non-photon actually will be magnified the light. In this case, as long as necessary with the equipment, you can have exactly the same form and frequency of the photon flow in the same direction, and that is laser. The optical amplification equipment, is the laser. In 1953, according to Einstein's principle of stimulated emission, the United States Townes physicist successfully developed a microwave amplifiers.
     In September 1960, and finally the laser in the United States in the hands of young physicists Maiman was born. Maiman's laser used a synthetic ruby as a light-emitting material to the laser as a light source. Ruby is a man-made crystal. When Maiman with Xenon flash exposure Ruby, the laboratory fired all of a sudden a bouquet of dark red light, the brightness of the sun to reach the surface brightness four times. This beam is exciting dazzling laser beam. After about six months, China has also developed a ruby laser. By the laser light-emitting material (medium), tube-like cavity and the laser source consists of three parts. Many substances can produce laser, but different material generated by the laser in different physical properties. Lasers work by firing a laser into the length of time in a row, pulse, giant ultra-short pulse and pulse four.

The characteristics of the laser

The first is characterized by - than the sun but also tens of billions of times more light and strong sunlight, heat, no one can dare to face up to the dazzling sun, but with the laser, the sun seems to pale into insignificance on the. Maiman made that Taiwan ruby laser, it emits the dark red laser is four times the brightness of the sun. In recent years, and the development of the latest laser, the solar surface brightness higher than 10,000,000,000 times!
Because the laser is a laser focus on the issue of the axis along the direction of the launch angle with a very small (only about one-tenth of the time), the brightness of the laser will power than with the hundreds of millions of times higher than ordinary light. Coupled with the use of lasers to special technology, in a very short period of time (such asÒ»ÍòÒÚ·ÖÖ®Ò»seconds) radiation great energy, and when it is in the convergence can produce millions of degrees, or even tens of millions of degrees of temperature .
The second feature - the color of pure sunlight into red, orange, yellow, green, green, blue and purple seven-color light. Different colors of the optical wavelength
Is not the same. In the natural world can not find in almost pure wavelength of light, a variety of wavelengths of light are always mixed together.
Scientists have long been trying to find a consistent single wavelength light source. This laser is an ideal single-color light source. Take helium-neon laser gas, of which InjectionÒ»°ÙÒÚ·ÖÖ®Ò»less than a micron wavelength width, and can be regarded as no loss of a single wavelength, the monochromatic light is very pure. The third feature - the direction of the largest concentration By the time we open a bright flashlight or search light, they appeared to shoot in the direction of the beam is straight, seems to be very concentrated, but in reality, when the beam reach a certain distance, Were scattered on the split. Laser is the only direction the most, the largest concentration of light. If the laser beam shooting at the moon, not only to spend only about 1 second will be able to reach the surface of the moon, and there is only one left with a radius of two kilometers of the spot area. The fourth feature - an excellent coherence
When the pool water will be hand-stirred wave and the wave of these peaks and crests Xiangdie, the water will aggravate the ups and downs, this phenomenon is called interference, to produce the interference wave is called wave interference. Laser light is a kind of coherence, and its wavelength, and so the same direction.
Physicists often use to indicate the length of the coherence of coherent light, the light source coherence length of the longer-ray
The coherence, the better. Coherent Laser and the length of up to several dozen kilometers. Therefore, if the laser will be used for precision measurement, and its maximum length of the test than the ordinary large monochromatic light more than 100,000 times. The laser is characterized by four interrelated and complementary.

Lueshi small technology

Scientists have the characteristics of the laser, so that the laser shows that modern science and technology on a large stage, it did three incredible wonders.
The first thing is strange piercing blue sky to the moon Kouxiang "Guanghan Gong," the door. In 1969, the United States for the first time the spacecraft by the astronauts to the moon. In fact, as early as the laser in 1962 on the Czech Republic have been enough to "landing" on the moon. The scientists are using a ruby laser beam. Laser reach Earth from the moon and then return to Earth from the moon, miles across the sky, come and go in just 2.6 seconds up. Scientists take this precious lens, taken under the laser's footprint on the moon - a bright red dot.
The second novel is to a laser beam eyes were drilling eye rule. Eyes like a camera, a pupil and the pupil after the lens is a light to enter the "window." As fine a line of laser beam, just from here into the eyes. Like crystal lens, it is the laser focus on the retina. The focus is very small, only a few dozen microns, the diameter of human hair and almost; high concentration of energy Therefore, the temperature can reach 1,000 degrees, and use it as a very high precision ophthalmic surgery was very satisfactory. For example, the eye's retina hole closed up. This type of surgery usually takes from the eye to pick out in the eyes so the patient is suffering; now use laser to "weld" at the lesion, according to a doctor switch, as long as one thousandth seconds on the hole can be closed well. The speed of the patients do not know surgery is over. The third novel in the 12 meters left lasers far put a 3 mm thick steel plate, the laser beam at the plate will be able to go on to play a small hole. It holes of the total energy released less than a 15-watt light artillery within 1 second issued by the energy of it.

The type of laser

Gas laser
In gas lasers, the most common is a helium-neon laser. The world's first helium-neon laser is the second after the first ruby laser in the near future, in 1960 in the United States, Bell Labs physicist from Iran million Jia made. As the helium-neon laser beam direction issued by the monochrome and good, you can work in a row, so that the use of lasers in today's largest laser, mainly used in the holographic precision measurement, positioning the collimator.
Laser gas in another is a typical representative of the argon ion laser. It can issue a bright blue-green light may be in a row, output power up to 100 watts. This laser is visible in the region's highest output power of a laser. Since it was issued by blue-green laser, so in the ophthalmic use most frequently, as blue-green to the human eye's response is very sensitive eye on the retina of heme, lutein can absorb green light. As a result, with argon ion laser eye surgeries for prompt formation of local heating will be turned into protein gel on the retina, it is an ideal source of welding the retina. Argon ion laser issued by blue-green laser can also layer of sea water depth, and not by absorption of water, which can be used in underwater survey operations.
Liquid, chemical and semiconductor optical invitation
Lasers also known as liquid dye laser, such as laser-activated some of the organic dye material is dissolved in ethanol, methanol or water in liquid form, such as the solution. In order to inspire them to launch a laser, generally used for high-speed flash of laser sources, or by other laser issued a very short light pulses. Liquid issued by the laser for laser spectroscopy, laser chemistry and other scientific research, is of great significance.
Chemical laser is a chemical reaction to produce the laser. Such as fluorine atoms and hydrogen atoms react chemically, to inspire a generation of the state of molecular hydrogen fluoride. In this way, when the two mixed gases rapidly to be able to have a laser and therefore do not need other energy from a chemical reaction will be able to get the very strong light. Comparing this type of laser suitable for field work, or for military purposes, it is the fear of death ray laser weapons and Applied Chemistry is a result.
In today's laser, and some are made of semiconductors. They called gallium arsenide semiconductor lasers, only the size of matchbox size, which is a micro-laser, the output wavelength of the human eye can not see infrared, between 0.8 to 0.9 microns. As a result of this laser small and simple structure, as long as appropriate to pass the current strength of the laser had fired, together with the output in the infrared wavelength light, so confidentiality is particularly virulent, it is suitable for use in aircraft, warships and tanks.
Solid-state laser
Mentioned in front of the ruby laser is a solid-state lasers. Early ruby laser is used as a common source Sources excited. Now the production of the ruby laser has developed many new products, more variety. In addition, the incentives approach is also divided into several, in addition to encouraging light, there are incentives discharge, thermal and chemical incentives, and other incentives.
Solid-state lasers are commonly used in YAG laser, it is the work of the material alumina and yttrium oxide synthesis of the crystal, mixed and neodymium oxide. By the laser crystal neodymium ions in the release, is the human eye can not see infrared light, can work in a row, or pulse mode. As a result of this relatively large laser output power, not only militarily useful, but also widely used in industry. In addition, YAG lasers or laser in the liquid dye laser for the treatment of cataract and glaucoma is very effective.
"Stealth" and "color" lasers. There are also two types of specialized lasers. One is carbon dioxide laser can be referred to as "stealth

"Because it is issued by the laser wavelength of 10.6 microns, the" body "in the infrared area, the naked eye can not detect it work there in a row, the two pulse. The way for laser power up to 20 kilowatts or more. Pulse Generated 10.6-micron wavelength of the laser is the most powerful of a laser. It has been used to "fight" a nucleus of neutrons. Carbon dioxide laser is the emergence of laser in the development of significant progress, but also light weapons and nuclear fusion research The significant results. The most common length of a carbon dioxide laser is about 1 meter of the discharge tube. Affixed at one end its gold-plated lens reflex, on the other side let affixed to a 10.6-micron infrared light through the lens of the plane as germanium infrared Laser output mirror. Usual glass lenses that let through infrared light, so do not mirror the output. Discharge tube discharge when pink spontaneous emission of light generated by the laser it is invisible, in the brick on brick sufficient to Issued by the spread of dazzling white light. Experiments, will accidentally burned their clothes and exposed skin burns to the face, so that such lasers are close to "dangerous" tag, the special operation Attention. Carbon dioxide laser in the form of a lot. Arrester up to a maximum of more than 200 meters, it is necessary to take a lot of space. Scientists find a way to the straight discharge tube bent back and forth turning point in the shape of the discharge tube or stack up the installation, They are down to the actual length of 20 meters or so; in order to make the laser optical vibration from the impact of the entire device placed in the basement of the large tube. Invention was known as a horizontal flow of carbon dioxide laser, only to shrink in length - Zhang As the length of a desk, be able to shoot a few kilowatts of laser power. Such lasers have been used in many auto plants processing large-scale tractor parts. Output power of a larger structure of the carbon dioxide laser as a large jet engine, running up a stereo sound scary, It can generate millions of watts of continuous laser is the way for the launch of the strongest laser.'s Initial target tanks laser experiment, this laser is used. It is the scientists and aerodynamic combination of laser science and manufacturing . Pulsed manner in order to launch the carbon dioxide laser also there are many in the industry and scientific research in a wide range of uses. If each pulse sent to compare the size of the energy, carbon dioxide laser pulse laser pulse is the strongest. Here, we have to return to the laser pioneer Townes has studied the issue up, to talk about mm
Wave generation. With laser technology, many scientists to this problem and launched an attack: the use or discharge of carbon dioxide laser as a powerful incentive to stimulate fluoride source of methane, ammonia gas, and other elements, step by step to launch out of the laser wavelength to extend , To expand. Began to reach tens of microns, and later reached a few hundred microns, which is a sub-millimeter wave. In the mid-60th century to the mid-70s, along with the development of microwave technology, scientists have a laser in accordance with the principles and methods of the millimeter wave. In this way, light waves from the microwave to the gap between the zone will continue to be found to fill the new laser infrared. From the study, scientists found that millimeter wave is very practical value: the atmosphere on its absorption rate is very small, it hindered the spread of the impact of small, you can use it to the atmosphere as a new communication tool. Another special, new laser, the image can be to call it the "chameleon." It is not long, however, will be able to change color; as long turning a knob on the laser, it can be red, orange, yellow, green, green, blue and purple color of the laser.
Is dye lasers have relations with it? It is also good. This laser is indeed the work of the dye material, such as carbon merocyanine, Rhodamine coumarin and so on. So far scientists have not yet clear about the dye molecules and atomic-level structure, they only know that the work of the gas and the gas Atom material, the structure of different ions; gas generated by the laser wavelength of a clear, and the resulting dye laser, the wavelength range over Canton, or a variety of colors. The dye laser optical cavity with a group called the grating in the optical components. It may need to select the color laser, just like the radio, listen to the election of a different frequency radio station broadcasting the same.
Dye laser light is a source of inspiration pump can be pulsed xenon lamp, you can use molecular nitrogen laser

Issued by the laser. A color for the optically pumped laser, the results of other colors to produce the laser can be said to be one of the characteristics of the dye laser.
This needs to change at any time can be generated by the laser wavelength of the laser, mainly for spectroscopy research; many of the material will be selectively absorbed certain wavelengths of light, have a resonance phenomenon. Scientists use these materials analysis, to understand the structure of the material; also use lasers to produce a new laser to study some of the strange phenomenon of optics and spectroscopy.

Juvenile laser scientists

While the laser is a brand-new modern invention, laser technology has become a cutting-edge technology, but it's by no means unattainable.
In the first year after the emergence of ruby lasers, the United States, Texas, there is a 15-year-old self-made by a ruby laser, in the middle school science exhibition was the first place.
He is a Excellence, like basketball, football, in the hands of the laser-based knowledge, they want to try a laser. The beginning, the scheme appeared to be unattainable. He was told that the idea of self-made laser unrealistic: Take the core of the laser - a ruby crystal, the value is by no means a high-school students can afford. But he was not discouraged, but the courage to give a few ruby crystal manufacturing company wrote a letter requesting help. Finally, there is finally a company to satisfy his desire, a well-packaged Ruby sent to stick his hand. As an aerospace engineer father, not only in spirit encouraged him to work, and asks you to engage in an electronic technology colleagues to give him guidance and help. The arrangement Youth every day after school extra-curricular work, the remaining time for the production of lasers. He spent 3 months the first time installed 4,000 high voltage power supply, followed by the installation of the main part of the laser, was a success. Laser came a red laser beam, can play a small hole on the blade.