Question

Anyone heard about Maser- microwave laser no bigger than a grain of rice ?

Answer 1

Researchers say they have built a microwave laser no bigger than a grain of rice that is powered by single electrons tunneling through artificial atoms known as quantum dots. The device, called a maser, could help make advances in communications, sensing, medicine and other aspects of modern life.The researchers weren't trying to build a mini-maser. The experiment actually was designed to explore the use of double quantum dots, joining two dots together to form qubits, the basic units of information in quantum computers.

Answer 2

The researchers used extremely thin nanowires made of indium arsenide to fabricate the quantum dots. They placed the qubits 6 milimeters apart in a cavity made from niobium at a temperature near absolute zero (459 degrees below zero Fahrenheit).The electrons flowed single-file through each dot, which emitted photons in the microwave region of the light spectrum. The photons bounced off mirrors on either side of the cavity, creating a beam of microwave light.The light produced can be fine-tuned to other frequencies, something semiconductor lasers cannot do.