Using a significant class of micro-comb called soliton crystals, scientists achieved ultra-high data transmission over 75 km of standard optical fiber using a single integrated chip source.
Transmission networks utilize various frequencies, or colors to transfer as much information as possible. Current networks typically need a separate laser for every color, which is difficult and costly to set up properly.
Here, scientists used a micro-comb to replace multiple lasers. Using this wave-comb as like as a hair comb, scientists can generate a set of equally different frequencies, and the phase and amplitude of which can be easily and precisely controlled. The ability to supply all wavelengths with a single, compact integrated chip, replacing many parallel lasers, offers the greatest benefit in terms of performance, scalability, and power consumption.
Professor Morandotti said, “We took advantage of the fact that a frequency comb could be created with a device known as a micro-ring resonator. Previous to this work, a well-behaved comb, resulting in a so-called cavity soliton, required a special and unique balance between color dispersion and non-linearity.”
“Such combs are typically difficult to generate and stabilize, and not power-efficient even under ideal conditions, so the researchers have developed a new way to achieve them for telecom purposes. In particular, if the microresonator is properly designed, it is possible to get a cross point between the optical modes supported by the device, which in turn creates the right condition for realizing a different type of micro-comb, leading to so-called crystal solitons, which is both robust and user-friendly.”
This work demonstrates the ability of optical micro-combs to act in demanding and practical optical communications networks. As indicated by Professor Morandotti, the proposed system could be commercially implemented in 5 years since similar micro-ring resonators, expected for less demanding applications; for example, filtering is already well known and commercially accessible.
- Corcoran, B. et al, Ultra-dense optical data transmission over standard fibre with a single chip source. DOI: 10.1038/s41467-020-16265-x