In 1915, Albert Einstein, based on Planck’s law of radiation, stated induced radiation, which gave the basis for the operation of lasers. Einstein was not thinking about the applications that this phrase might have.
Like all of Einstein’s theories, an attempt has been made to prove it experimentally. In 1928, Rudolf Landenberg announced that he had obtained evidence of induced radiation. Despite its importance, this went unnoticed. Later Willis Eugene Lamb and R. C. Rutherford confirmed its existence. In 1960, Charles Townes and Arthur Leonard Shawlow operated and patented a laser. Several groups were trying this, and may have achieved this before, but at the time communications between scientists were not very effective.
From this moment, there was a major technological development that allowed it to be used in many fields. In 1980, it began to be used on CDs, then on DVDs and Blue Ray discs, which revolutionized the storage of data of all kinds, due to its accuracy and enormous storage capacity. Let’s remember that data was stored on magnetic tapes and floppy disks, which were fragile and unreliable.
Lasers are used in barcode readers and precision cutting machines. Laser pointers and distance meters are very common.
Its use has extended to other fields such as medicine, where it is used in various surgical operations, perhaps the most famous of which is eye surgery. It is also used to repair tissues, destroy malignant cells, relieve pain, etc.
In astronomy they are used to align telescope mirrors (colimar), to measure turbulence in the atmosphere and get an idea of the quality of the images to be taken and to measure the distance between the Earth and the Moon, among other things.
It was recently reported that NASA received a laser signal on Earth that came from space. This signal was sent from the Psyche probe, which was 16 million kilometers away, and received by the Hale Telescope in California. The transmitted signal contains encoded information that can be properly decoded and read. This ship will meet an asteroid of the same name located in the main belt to study its chemical composition.
Why did NASA do this test? Lasers are already used on Earth to transmit data. It is a very effective and fast way to do this. What you want is to try it when the distances are much greater. It is NASA’s Deep Space Optical Communications (DSOC) project. The way data is transmitted in space is traditionally done using radio waves in a reliable way, but some information is always lost. With a laser, which is an optical transmitter, there is less loss of information and, most importantly, it can transmit between 10 and 100 times more information, which is very important, because from space essentially increasingly larger images are transmitted. . It takes nine weeks to transmit a complete map of Mars by radio frequency; With laser, this will be done in nine days. Another advantage is that laser transceivers are lighter and smaller than radio frequency transceivers, making them more suitable for use on spacecraft.
Let us remember that when Einstein presented the foundations of stimulated radiation, those who were able to do it in the laboratory were not thinking about its applications, they were simply doing so to learn more about the subject. This is basic science research, which can later be applied to different things. If Einstein had not done this and no one else had been interested in the subject, lasers might not have been known today. This shows the importance of basic research.
