Spaser- The Smallest Laser Ever
One of the emerging concepts in the field of nanotechnology is spaser. Spaser means ‘Surface Plasmon amplified by stimulated emission of radiation’. The phenomenon was first introduced by Bergman and Stockman in 2003. The first spaser device is made with a gold nano particle surrounded by a dyed silica gain medium in the year 2009. The introduction of spaser technology is a great milestone in the field of electronics and nanotechnology.
Working of Laser
Before going to spaser you must know about the working of ‘Laser’. Laser means ‘light amplified by stimulated emission of radiation’. The apparatus consist of a gain medium in which light of specific wavelength is amplified. It contains two mirrors at either end of the apparatus where the light is reflected back and forth, so that each time the light gets amplified. One of the mirrors is partially reflected so that some of the amplified light comes out from the apparatus.
The concept of spaser is different from laser. Light is amplified in the production of laser whereas surface Plasmon is amplified in the production of spaser. In a single words surface Plasmon is a bundle of electrons. When light falls on the surface of a metal the electrons are ejected from the atom. But when a dielectric is bordered with the metal the electrons cannot jump into the dielectric because it is a non conductor. Instead of this, these electrons form an electron density wave in the surface of the metal and moves along the surface. The study of these electron density waves is called Plasmonics. This electron density wave is then amplified and it produces spaser.
The apparatus used to produce spaser is 1/10th of size of the wavelength of radiation produced by it. For example if the apparatus is about 50 nm size then the wavelength of light produced by it is about 530 nm, I.e. about 10 times. This is the main advantage of spaser over laser. For a laser beam to produce of wavelength 500 nm the apparatus size should be a minimum of 250 nm is required. Which means the wavelength of light produce by an apparatus of laser is only 2 times that of its size.
Advantages of spaser
One of the main advantages of spaser is that it can reduce the size of the transistors and other electronic components. The speed of the spaser is thousand times faster than a normal transistor. With spasers, it can produce ultrafast amplifiers and microprocessors than the normal microprocessors. Spasers can be used in place of the normal laser when it is become successfully introduced in the field of electronics.
One of the other uses of spaser is in the field of optical computing. Spaser can be also used in the field of medical for the treatment of cancer cells.