Last updated on July 6th, 2021
1. The first laser was built by Theodore H Maiman in 1960 at Hughes Research Laboratories and was based on the theoretical work of Charles Hard Townes and Arthur Leonard Schawlow. Before lasers were invented there were ‘masers’ which used a similar technique for microwave radiation and were based on Albert Einstein’s theory of stimulated emission of radiation.
2. The word laser is an acronym for Light Amplification by Stimulated Emission of Radiation. It works by controlling how energized atoms release photons; they operate by pumping electrical discharges (that produce intense flashes of light) through a lasing medium to create a large number of excited state atoms that contain high-energy electrons.
3. The strength of early lasers was measured in ‘Gillettes’ which was a measure of how many razor blades a laser beam could penetrate. Today, the world’s most powerful lasers can direct as much power as a hydrogen bomb.
4. Laser beams have been developed that are precise and powerful enough to etch a tiny serial number onto diamonds (which are the hardest substance known) and can generate higher temperatures than those at the surface of the sun.
5. Scientists are experimenting with huge, 2 foot wide, lasers that are designed to reproduce conditions on the surface of the sun at the National Ignition Facility (which featured in one of the Star Trek movies).
6. Speaking of Star Trek, the first commercial toy to use laser technology was a phaser gun which featured on the show and produced a very weak laser beam.
7. The ability of lasers to focus light with intense power at very precise areas makes them excellent tools for cutting, welding and even performing surgery on human beings.
8. Laser cutting equipment uses mirrors and lenses to focus a highly concentrated beam onto materials to cut them very accurately. This can include plastics, acrylics, wood, brass and various other types of metal such as steel, stainless steel and aluminum.
9. Laser cutting equipment is highly accurate and can be used to engrave to a microscopic level. Scientists have found that lasers are accurate to more than a nanometer which is one billionth of a meter.
| LASER TYPE | WAVELENGTH (Nanometers) |
|---|---|
| Argon Fluoride | 193 |
| Xenon Chloride | 308 and 459 |
| Xenon Fluoride | 353 and 459 |
| Helium Cadmium | 325 - 442 |
| Rhodamine 6G | 450 - 650 |
| Copper Vapor | 511 and 578 |
| Argon | 457 - 528 (514.5 and 488 most used) |
| Frequency doubled Nd:YAG | 532 |
| Helium Neon | 543, 594, 612, and 632.8 |
| Krypton | 337.5 - 799.3 (647.1 - 676.4 most used) |
| Ruby | 694.3 |
| Laser Diodes | 630 - 950 |
| Ti:Sapphire | 690 - 960 |
| Alexandrite | 720 - 780 |
| Nd:YAG | 1064 |
| Hydgrogen Fluoride | 2600 - 3000 |
| Erbium:Glass | 1540 |
| Carbon Monoxide | 5000 - 6000 |
| Carbon Dioxide | 10600 |
| Table data source | Fas.org |
| Table last updated | 28/06/2021 |
10. Lasers have been used in a wide range of consumer technologies such as optical disk drives, barcode scanners, fibre optics, manufacturing computer chips and as lighting displays for entertainment.
11. Lasers can be used as spectrometers which are devices that use light to determine the specific chemical components in different types of matter. When laser light passes through a gas made from matter it reflects certain colors in specific wavelengths that are then studied to identify the different elements that are present in it.
12. A laser was used to provide an accurate measurement of the distance from the earth to the moon. During the Apollo 11 mission to the moon astronauts placed reflectors on the moon which enabled earth-based lasers to be fired at them to get an extremely accurate measure of the distance between the two bodies.
13. Lasers have found applications in law enforcement. They are used in speed cameras to determine whether drivers are exceeding the speed limit. Lasers are also used for latent fingerprint detection and are much more accurate than previous methods that were used.
14. Lasers can be used to treat cancers by destroying or shrinking cancerous tumors or growths that appear before cancer develops. They are most often used to treat cancers that are on the surface of the body or those that occur in a person’s internal organs.
15. Lasers have also been developed that can determine whether a patient is suffering from cancer or diabetes; the tool is called a breathalyzer (but is not the same as machines that test for alcohol).
16. Lasers are classified by the amount of output power of the light pulses they use. Laser pointers, CD-ROM drives and DVD players use between 1 and 10mW. Lasers used for burning CDs use between 100mW and 400mW. Lasers used for cutting and machining can use up to 3000W of light power.
17. The most powerful laser ever created produced a beam with a peak power of 2000 trillion watts (2 petawatts) at Osaka University in Japan recently. Because of its massive power it was only fired for an extremely short duration: about a trillionth of a second (or picosecond).
18. Lasers are classified into different safety class numbers which reflect how dangerous they are. These range from class 1, which are inherently safe, to class 5 which have the potential to burn skin and cause eye damage.
19. Lasers have featured in many films and popular culture as their use has become more widespread. One of the first, and most famous, examples was in the 1964 James Bond movie Goldfinger where the eponymous spy was threatened with being cut in half by one.
20. Lasers can be used in the sequencing of DNA. They are so accurate that it is possible to get the sequencing information contained in a single molecule.
21. Lasers have had military applications and there are many weapons used that rely on laser-targeting because of the technique’s ability to deliver ordnance precisely. The first laser-guided bomb as the Bolt-117 produced in 1967.
22. Lasers are being studied by scientists for their ability to draw lightning strikes away from sensitive buildings and structures such as airports and power plants.
23. Laser lights can’t be seen in space because they do not consist of any matter; matter is required to give the scattering effect which makes them visible.
24. Laser beams have been developed by scientists that can now be used to manipulate objects by using very small and highly focused beams.
25. Living cells have also been used to produce laser light. This was done by genetically engineering cells that produce a green fluorescent protein which was used to provide the light amplification. Cells were placed between two tiny mirrors (a 20 millionths of a meter wide) and, once they were bathed with light, they emitted a green laser light.