The nanomembrane itself is made of silicon nitrate and is coated with a thin layer of aluminum, because there has to be a metallic substance to better interact with the electric field. The membrane is separated from the surroundings by being enclosed in a vacuum chamber so that it responds as if it had been cooled down to two degrees Kelvin (minus 271 C). Credit: Ola Jakup Joensen, NBI
The supersensitive device holds promise for medical imaging and quantum networks
Physicists have found a way to detect faint radio waves and convert them directly into signals that can be transmitted by fiber optics. The discovery could improve the sensitivity of detectors used in magnetic resonance imaging and radio astronomy, and help to connect future quantum computers into a network.
Radio-wave receivers use antennas to pick up radiation. The incoming waves resonate with the antenna and induce a changing electrical signal, which is then transmitted down a wire. Faint radio signals must be boosted by electrical amplifiers such as transistors, which introduce noise — extra fluctuations that, when amplified, can swamp the signal. The amount of noise present sets the limit of the detector’s sensitivity: The best amplifiers must be super-cooled to reduce the thermal vibrations that cause noise.
A team led by physicist Eugene Polzik at the University of Copenhagen’s Niels Bohr Institute has now created a detector that can turn radio signals into optical signals at room temperature, without the need to go through amplification. The device is already as sensitive as state-of-the-art electronics, says Polzik.
Up and down
The key to the approach, described in Nature, is a membrane of silicon nitride less than 200 nanometers thick, coated with aluminium and suspended over a gold plate. When an antenna picks up a radio signal, it creates an oscillating electrical signal in the circuit. This produces a voltage flicking back and forth between the aluminium and the gold, and the resulting attracting and repelling electrostatic forces cause the membrane to move in tune with the wave.
The device detects this motion by bouncing a laser off the membrane and measuring how the motion shifts the laser’s light waves, explains co-author Albert Schliesser, also a physicist at the Niels Bohr Institute. This laser signal can be read out, and its accuracy is limited only by quantum fluctuations of the laser light, he says. Tests show that noise from the membrane is tiny: even at room temperature, the membrane adds 100 times less noise than super-cooled electronic amplifiers, says Schliesser.
Previous experiments have succeeded in converting radio-frequency signals into mechanical vibrations, and in turning mechanical vibrations into light signals, but Schliesser and his colleagues have combined both into a single system.
The Latest on: Supersensitive sensor
via Google News
The Latest on: Supersensitive sensor
- Fujifilm X-H2S review: built for speedon July 29, 2022 at 3:31 am
Fifth-gen X-Series gets an ergonomic overhaul and rapid continuous shooting abilities. The X-H2S is Fujifilm's best APS-C model yet ...
- Super Sensitive Electronic Skin for Prosthetic Deviceson July 17, 2022 at 4:59 pm
“ACES can be easily paired with any kind of sensor skin layers, for example, those designed to sense temperatures and humidity, to create high performance ACES-enabled electronic skin with an ...
- The best electric toothbrushes in 2022on July 15, 2022 at 12:45 pm
The seven modes include daily clean, intense clean, whitening, gum care, sensitive, super sensitive and tongue ... out if and how well a pressure sensor indicator (letting you know if you are ...
- Breathe easy with these Prime Day deals on air purifiers — starting at just $31on July 12, 2022 at 1:22 pm
Sensor works fine. If it detects unhealthy ... It is quiet and effective...It is super sensitive. We have it near a window where on the outside porch people sometimes smoke ...
- Huawei Mate 50 series has been finalized – here are the key pointson July 11, 2022 at 9:52 pm
Imaging technology is an intersection of photoelectric conversion, including RYYB super-sensitive sensor, full-pixel octa-core focusing, 10-channel multispectral sensor, hyperspectral imaging ...
- Enjoy $90 off the Oral-B iO Series 9 this Prime Day – tried and testedon July 8, 2022 at 9:06 am
This top-of-the-range electric toothbrush comes with a host of smart features, including a pressure sensor ... This includes sensitive and super sensitive modes for those with more sensitive ...
- DIY Graphene Putty Makes Super Sensitive Sensoron June 8, 2022 at 5:00 pm
In addition to just making a pliable sensor, you can also embed monofilament line into the putty and make super sensitive artificial cilia. Just the thing for your next artificial alien project.
- The best compact camera 2022: 16 best pocket cameras to buyon March 18, 2021 at 1:26 am
That sensor means it shoot 4K video ... from 30fps shooting at full resolution to a super-sensitive touchscreen, in-camera Raw processing and the added convenience of USB charging.
via Bing News