The laser today and tomorrow

1. The laser has become a multipurpose tool. It has caused a real revolution in technology.

Atoms emit rays of different length, which prevents the forming of an intense beam of light. The laser forces its atoms to emit rays having the same length and travelling in the same direction. The result is a narrow, extremely intense beam of light that spreads out very little and is therefore able to travel very great distances.

2. The most common laser is the helium-neon laser in the laser tube, containing 10 per cent helium gas and 90 per cent neon gas. At the end of the tube there is a mirror, and at the other end there is a partial mirror. The electrons get energy from a power supply and become “excited”, giving off energy as light. This light is reflected by the mirror at one end of the tube. It can only escape through the partial mirror at the other end of the tube.

3. The first laser was built in 1960. Since then scientists have developed several types of the laser which make use of luminescent crystals, luminescent glass, a mixture of various gases and finally semiconductors.

4. Having been developed at The Institute of Physics in 1962, semiconductor quantum generators occupy a special place among the optical generators. While the size of the ruby crystal laser comes to tens of centimeters and that of the gas generator is about a meter long, the semiconductor laser is a few tens of a millimeter long, the density of its radiation being hundreds of thousands of times greater than that of the best ruby laser.

5. But the most interesting thing about semiconductor laser is that it is able to transform electrical energy directly into light wave energy. The semiconductor laser opens up new possibilities of producing extremely economical sources of light.

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What possibilities does the semiconductor laser open?

Вариант 3.

I. Перепишите и письменно переведите на русский язык следующие предложения. Помните, что объектный и субъектный инфинитивные обороты соответствуют придаточным предложениям (см. образец выполнения 1).

1. The Sun and stars are proved to be able to produce great quantities of energy by means of certain nuclear reactions.

2. For the experiment we need several electrical devices to be connected in series.

3. Lasers are known to have found wide application in medicine.

II. Перепишите и письменно переведите на русский язык следующие предложения. Обратите внимание на перевод зависимого и независимого (самостоятельного) причастных оборотов (см. образец выполнения 2).

1. Measurements of solar radiation reaching the Earth each day make it possible to calculate the surface temperature of the Sun.

2. Having built a new automobile plant, we increased the output of cars and buses.

3. Knowledge being the most valuable wealth of our times, the information theory became of great importance for the national economy.

III. Перепишите и письменно переведите на русский язык следующие сложные предложения. Обратите внимание на перевод условных предложений (см. образец выполнения 3).

1. If the gathered data had been presented in time, the results of the experiments would have been different.

2. If you had answered six questions in the competition, you would have won the first prize.

3. It would be impossible to carry on a careful study of the process without the new device.

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Пояснения к тексту.

1. digital - цифровой

2. to result in – заканчиваться, приводить к чему-либо

3. prospects – перспективы