The plasmonic cavities have a view. The gold film is sandwiched between the grooves and a large nanoparticles. The pump laser providing energy for upconversion comes from the top, while the IR signal comes from below. Both are focused on the molecule, and interact with their internal frequencies to generate an upconverted copy of the signal at visible frequencies. Nicolas Antille has aTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkiaTrademarkia
Light is a wave of electric and magnetic fields. The number of oscillations per second is the basis of the wave's description. The visible spectrum can be defined by frequencies between 400 and 750 trillion Hz. Light sensors in cell phone cameras can detect frequencies as low as 300 THz, while internet connections through optical fibers can detect up to 200 THz.
It's a problem given that there is rich information available at frequencies below 100 THz, the mid- and far-infrared spectrum. A body with a surface temperature of 20C emits light up to 10 THz, which can be seen with thermal imagery. Chemical and biological substances have absorption bands in the mid-infrared that can be identified remotely and non-destructively.
The light is turning into visible light.
The scientists at EPFL, Wuhan Institute of Technology, the Valencia Polytechnic University, and AMOLF in the Netherlands have developed a new way to detect visible and IR light. The device can extend the sight of commonly available and highly sensitive detectors. Science published the breakthrough.
It's not easy to convert a Frequency into another Frequency. Light cannot be reflected on a surface or passed through a material because of the law of energy efficiency.
The researchers added energy to the light with tiny vibrating molecule. The light is directed to the molecule where it converts into energy. A laser beam of higher frequencies is able to provide extra energy and light up the space by hitting the same molecule. The molecule are sandwiched between metallic nanostructures that act as optical antennas to boost the conversion process.
A new light.
The new device has a number of appealing features, according to the study leader. The conversion process is coherent, meaning that all information from the original light is mapped onto the new light. It allows for the use of standard detectors like those found in cell-phone cameras. Each device is about a few micrometers in length and width, which makes it possible to put it into a large array. The method can be adapted to different frequencies by simply choosing the right molecule.
The device's light-conversion efficiency is still very low, cautions Dr. Wen Chen, the first author of the work. "We are concentrating our efforts on improving it." This is a crucial step in the process of commercial applications.
There is more information about the Continuous-Wave Frequency Upconversion with aMolecular OptomechanicalNanocavity. www.science.org/doi/10.1126/science.abk3106
Science journal information.
Themolecular device turns IR into visible light on December 2 and December 2, 2021.
The document is copyrighted. Any fair dealing for the purpose of private study or research cannot be reproduced without written permission. The content is not intended to be used for anything other than information purposes.
