Lasers are a special kind of device and when they were first created, they opened a new world to scientists of many fields. Since that day they have evolved as techniques improved and new technologies replaced old. Now researchers at the University of Michigan have created a completely new kind of laser that technically is not a laser because of how different it is.
Originally 'laser' was not a word but an acronym standing for Light Amplification by the Stimulated Emission of Radiation. This new device however operates quite differently as it uses polaritons to generate the photons, instead of other photons. This technique was first proposed in 1996 and works by electrically exciting electrons to higher energy states, creating an exciton; an electron-hole pair. By carefully tuning the microcavity these excitons are in and subjecting them to a magnetic field, it is possible to couple them to a photon, making them into polaritons. What that translates to is that when the electron and hole recombine, they will release a photon of a specific frequency. This fails to meet the definition of a laser because one photon does not cause other photons to be released.
While it may not technically be a laser, it could eventually be used to replace them as it can operate using 1000 times less energy. Before we can see them being used in modern electronics and networks though, they will have to be redesigned to function at room temperature, as they currently require cryogenic temperatures.
Source: University of Michigan