Continuous-wave room-temperature diamond maser

TL;DR

This paper reports the first continuous-wave room-temperature diamond maser using optically pumped NV centers, demonstrating a significant advancement in solid-state maser technology with potential applications in microwave devices.

Contribution

It introduces a novel CW room-temperature maser oscillator based on diamond NV centers, overcoming previous pulsed operation limitations and expanding practical applications.

Findings

First CW room-temperature diamond maser demonstrated

Operates using optically pumped NV defect centers

Potential for new microwave device applications

Abstract

The maser, older sibling of the laser, has been confined to relative obscurity due to its reliance on cryogenic refrigeration and high-vacuum systems. Despite this it has found application in deep-space communications and radio astronomy due to its unparalleled performance as a low-noise amplifier and oscillator. The recent demonstration of a room-temperature solid- state maser exploiting photo-excited triplet states in organic pentacene molecules paves the way for a new class of maser that could find applications in medicine, security and sensing, taking advantage of its sensitivity and low noise. However, to date, only pulsed operation has been observed in this system. Furthermore, organic maser molecules have poor thermal and mechanical properties, and their triplet sub-level decay rates make continuous emission challenging: alternative materials are therefore required. Therefore, inorganic materials containing spin-defects such as diamond and silicon carbide have been proposed. Here we report a continuous-wave (CW) room-temperature maser oscillator using optically pumped charged nitrogen-vacancy (NV) defect centres in diamond. This demonstration unlocks the potential of room-temperature solid-state masers for use in a new generation of microwave devices.