The amount of communication on the Internet, which has increased rapidly due to the spread of personal computers and smartphones, is supported by optical communication technology.However, the signal sent as light must also be finally converted into an electrical signal before processing, resulting in energy loss due to heat generation.To solve these problems, photonics technology replaces the circuit that processes electrical signals with an optical signal processing circuit.Photonic crystals, which can confine light in a small nanoscale space, are considered to be promising candidates as materials for photonics technology.How to manufacture precision products at low cost is a big issue in the spread of technology.

A photonic crystal is a thin film of silicon with regular nanoscale holes.Until now, it has been produced by an expensive and time-consuming method called electron beam lithography.On the other hand, although the photolithography method is inferior in terms of precision, it is inexpensive and suitable for mass production.In this research, we succeeded in improving the accuracy by adopting a structure called width change type.We also confirmed that the elements made in this way show sufficient performance to perform all-optical signal processing.

　If all parts of information processing can be replaced with optical signal processing circuits, energy loss due to heat generation of electronic circuits can be reduced.If high-quality photonic crystals can be mass-produced at low cost, the ultimate power-saving integrated circuit will be realized soon.

Source:[Keio University] Achieved the world's highest performance of nano-optical resonators manufactured by CMOS process.