The reporter learned from the Research Institute of Precision Measurement Science and Technology Innovation of the Chinese Academy of Sciences that the second level frequency stability index of the new rubidium atomic clock developed by Mei Ganghua's research team of the Academy has entered the E-14(one millionth of a billion)level for the first time.The relevant paper was recently published in the international journal"Journal of Instrumentation and Measurement of the Society of Electrical and Electronics Engineers".
  Mei Ganghua introduced that frequency stability is the core indicator of atomic clocks,which directly affects the timing accuracy of atomic clocks.Rubidium atomic clocks are currently the ones with a high market share and are widely used in fields such as satellite navigation,communication,power,and finance.At present,the second level stability of commercial rubidium atomic clocks is in the range of E-11 to E-12.
  To further improve the frequency stability of rubidium atomic clocks,the research team started from three aspects:improving the signal-to-noise ratio of atomic signals,reducing the phase noise of microwave exploration,and suppressing the environmental sensitivity of atomic systems.In the physical system design of rubidium atomic clocks,new technologies such as slotted tube microwave cavities with independent intellectual property rights,large-sized rubidium bubbles,high spectral purity pump light sources,and dual filters were adopted,significantly improving the signal-to-noise ratio of atomic signals.In circuit design,researchers have adopted a new low phase noise frequency synthesizer design scheme to reduce the impact of microwave circuit noise on the frequency stability of rubidium atomic clocks.The researchers also used sealed boxes to isolate the physical system from the atmospheric environment,reducing the impact of atmospheric pressure fluctuations on the frequency stability of rubidium atomic clocks by an order of magnitude.Based on the above technologies,the research team has developed a new prototype of rubidium atomic clock principle.The measurement results show that the second level frequency stability of the atomic clock is 9E-14,and the hundred second level frequency stability is 9E-15.
  Mei Ganghua introduced that this technological breakthrough has further expanded China's leading advantage in rubidium atomic clock technology,and is of great significance for the development of high-quality microwave oscillator technology and the development of a new generation of Beidou system spaceborne atomic clocks.