Lasers are widely used in household appliances, medicine, industry, telecommunications and more. Several years ago, scientists introduced nanolasers. Their design is similar to that of the conventional semiconductor lasers based on heterostructures in common use for several decades. The difference is that the cavities of nanolasers are exceedingly small, on the order of the wavelength of the light they emit. Since they mostly generate visible and infrared light, the size is on the order of one millionth of a meter.