A two-channel atomic radio receiver. A mixture of cesium and rubidium is excited to Ryberg states and probed for changes in optical transparency at two different frequencies with lasers of different wavelengths. Source: C.L. Holloway, M.T. Simons, A.H. Haddab, C.J. Williams, and M.W. Holloway, AIP Advances 9, 065110 (2019). https://doi.org/10.1063/1.5099036
Many thanks to SWLing Post contributor, Paul W4/VP9KFPaul W4/VP9KF, who writes:
A very exciting radio! One that depends on excited atoms, of a sort…
The basic technology of radio hasn’t changed much since an Italian marquis first blasted telegraph messages across the Atlantic using a souped-up spark plug and a couple of coils of wire. Then as now, receiving radio waves relies on antennas of just the right shape and size to use the energy in the radio waves to induce a current that can be amplified, filtered, and demodulated, and changed into an audio waveform.
That basic equation may be set to change soon, though, as direct receivers made from an exotic phase of matter are developed and commercialized. Atomic radio, which does not rely on the trappings of traditional radio receivers, is poised to open a new window on the RF spectrum, one that is less subject to interference, takes up less space, and has much broader bandwidth than current receiver technologies. And surprisingly, it relies on just a small cloud of gas and a couple of lasers to work.
Tuning into Atomic Radio: Quantum Technique Unlocks Laser-Based Radio Reception
Click here to read the full article at Hackaday.
(Source: arstechnica via Scott Schad)
A new antenna using single atoms could usher in the age of atomic radio
The team tested their device by recording themselves singing “Mary Had a Little Lamb”
In the 1950s, atomic clocks revolutionized precision time-keeping. Now we may be on the verge of so-called “atomic radio,” thanks to the development of a new type of antenna capable of receiving signals across a much wider range of frequencies (more than four octaves) that is highly resistant to electromagnetic interference.
An antenna is typically a collection of metal rods that pick up passing radio waves and convert their energy into an electrical current, which is then amplified. One might argue that the good old-fashioned radio antenna has served us well since the dawn of the 20th century, so why do we need anything to replace it?
According to David Anderson of Rydberg Technologies, those antennae are wavelength-dependent, so their size depends on whatever wavelength of signal they are trying to measure (they need to be about half the size of whatever wavelength they are designed to receive). That means you need antennae of several different sizes to measure different radio frequencies.
Anderson is a co-author of a new paper posted to the arXiv describing a novel alternative to conventional antennae, based on vapor cells filled with a gas of so-called “Rydberg atoms.” That just means the atoms are in an especially excited state, well above their ground (lowest-energy) state. This makes them especially sensitive to passing electric fields, like the alternating fields of radio waves. All you need is a means of detecting those interactions to turn them into quantum sensors.[…]
Read the full article at arstechnica.
Click here to download the research paper: An atomic receiver for AM and FM radio communication (PDF).