What is a laser?
The word "LASER" is actually an acronym, standing for "Light Amplification by Stimulated Emission of Radiation. A laser is a kind of generator of light. As its acronym implies, the key ingredient of any laser is an optical amplifier—a device that strengthens light waves. This feature distinguishes lasers from other more familiar light sources such as light bulbs or the sun. Lasers typically produce well-directed light beams of a very specific color. Many lasers are designed to produce very short pulses of light.
The word laser is also used in a generic sense, indicating a similar device that works in a different wavelength range. Thus we have infra-red lasers and x-ray lasers. Read more.
Who made the first laser?
Theodore Maiman demonstrated the first working laser at Hughes Research Lab on May 16, 1960, and his paper describing the operation of the first laser was published in Nature three months later. More detailed information on the early history of the laser. Read an article written by maser/laser pioneer Charles Townes.
How does a laser work?
Although many different types of lasers are now in use today, Theodore Maiman's first ruby laser provides a good example of how lasers work:
In a ruby laser, a ruby crystal is formed into a cylinder. A fully reflecting mirror is placed on one end and a partially reflecting mirror on the other. A high-intensity lamp is spiraled around the ruby cylinder to provide a flash of white light that triggers the laser action.
The green and blue wavelengths in the flash excite electrons in the chromium atoms to a higher energy level. Upon returning to their normal state, the electrons emit their characteristic ruby-red light. The mirrors reflect some of this light back and forth inside the ruby crystal, stimulating other excited chromium atoms to produce more red light, until the light pulse builds up to high power and drains the energy stored in the crystal—this produces what we typically think of as "laser light".
What are lasers used for?
Today, lasers are used in countless areas of modern life. Some examples include telecommunications, medical diagnostics and surgery, manufacturing, environmental sensing, basic scientific research, space exploration and entertainment . Details on specific laser technologies being used in these areas and many more.
What are some future uses of lasers?
Scientists and engineers continue to find new uses for the laser everyday. Some wide-reaching areas on the horizon for laser technology include improved cancer diagnoses, faster Internet speeds, clean sources of energy, black hole exploration and much more. Read more.