Integrated Microwave Photonic Crystal On-Chip:Design,Fabrication And Testing

Photonic crystal is usually composed of periodic arrays of materials with different dielectric constants.Electromagnetic waves passing through this periodic special structure will be affected by Bragg scattering,and the transmission characteristics will be forbidden in a specific frequency band.As a device that can control the movement of photons,photonic crystal has many important applications in optical and microwave devices,such as photonic crystal laser,photonic crystal fiber,broadband filter and high-performance microstrip antenna.For a long time,the research on photonic crystal has focused on discrete devices,which are often large in size and have poor compatibility with each other.And the vast majority of these devices can only work in the normal temperature environment,can not work in the low-temperature superconducting environment,so it is difficult to achieve the application in the quantum field.To solve these problems,a series of studies have been carried out on the integrated microwave photonic crystal on chip working in ultra-low temperature superconducting environment.A microwave photonic crystal on chip based on waveguide resonator array was successfully fabricated on sapphire substrate by using integrated circuit planar processing technology.The microwave transmission characteristics of the samples were tested on the laboratory low temperature test platform.The band gap with a depth of about 25 d B and a band gap width of about150 MHz,centered at 5.15 GHz,was observed.The experimental result consists with the design.It is worth mentioning that the aluminum metal lines in the photonic crystal samples show superconducting state in the ultra-low temperature test environment of about 50 mk,which greatly reduces the impact of thermal noise on the weak photon flow.Therefore,as a low-temperature superconducting device,the photonic crystal prepared in this paper is mainly for superconducting quantum information processing and other applications,and is expected to play an important role in the development of superconducting quantum computer.