Scientists from the United States have developed a new solution to improve the efficiency of wavelength conversion. To do this, they used an undesirable but natural phenomenon – the surface state of a semiconductor.
Researchers at the University of California have developed a more efficient way to convert light from one wavelength to another, which opens up opportunities for improving the performance of imaging, sensing, and communication systems. A team of experts presented a solution to improve the efficiency of wavelength conversion by studying an undesirable but natural phenomenon – the surface state of a semiconductor.
These conditions occur when surface atoms have insufficient number of other atoms with which they can bind, resulting in a disruption of the atomic structure. These incomplete chemical bonds create barriers to electrical charges passing through semiconductor devices and affect their performance.
“There have been many attempts to suppress the effect of surface states in semiconductor devices, not realizing that they have unique electrochemical properties that can provide unprecedented device functionality,” the scientists noted.
“Thanks to the new structure, wavelength conversion occurs easily and without an additional source of energy when the incoming light crosses the field,” the scientists note.
The researchers successfully and efficiently converted a beam of light with a wavelength of 1,550 nanometers to the terahertz part of the spectrum with wavelengths ranging from 100 micrometers to 1 millimeter. The team demonstrated the efficiency of wavelength conversion by incorporating new technology into an endoscopic probe that can be used for detailed imaging and in-vivo spectroscopy using terahertz waves.
Without this method of wavelength conversion, obtaining the same terahertz waves would require 100 times more optical power, which cannot be provided by the thin optical fibers used in an endoscopic probe.