Nanostructures allow you to create a light-wave electronic frequency mixer on a crystal!

Imagine how a phone call works: your voice is converted into electronic signals, raised to higher frequencies, transmitted over long distances, and then lowered again so that it can be clearly heard at the other end of the wire. The process that provides such a signal frequency shift is called frequency mixing, and it is important for communication technologies such as radio and Wi-Fi. Frequency mixers are vital components of many electronic devices and usually operate at frequencies that range from billions (GHz, gigahertz) to trillions (THz, terahertz) once a second.

Development of new miniature light wave electronic circuits capable of processing optical signals directly at the nano level.

In the 1970s, scientists began to study ways to extend electronic frequency mixing to the terahertz range using diodes. Although these first efforts were promising, progress has stagnated for decades. However, recent advances in the field of nanotechnology have reactivated this field of research. The researchers found that tiny structures, such as the tips of nanometer-long needles and plasma antennas, can function similarly to those early diodes, but at much higher frequencies.

A recent study published in the journal Science Advances by Matthew Jung, Lu-Tin Chow, Marco Turchetti, Felix Ritzkowski, Karl K. Berggren and Philip D. Kitley from the Massachusetts Institute of Technology demonstrated a significant step forward. They developed an electronic frequency mixer for signal detection, which operates at frequencies above 0.350 FHz, using tiny nanoantennas. These nanoantennas can mix different frequencies of light, allowing you to analyze signals that fluctuate orders of magnitude faster than the fastest available to traditional electronics.

Although this study focused on the characterization of light pulses of different frequencies, the researchers suggest that such devices will allow creating circuits using light waves. This device with a bandwidth covering several octaves can provide new ways to study ultra-fast interactions of light and matter, accelerating the development of ultra-fast source technologies.

This work not only expands the boundaries of optical signal processing capabilities, but also closes the gap between the fields of electronics and optics. By combining these two important areas of research, this research paves the way for new technologies and applications in areas such as spectroscopy, visualization and communication, which ultimately expands our ability to explore and manipulate ultra-fast light dynamics.