Xi Qin et al., has proposed and implemented a timing generation method, and realized an arbitrary timing generator with a 5 picoseconds (10^-12 s) time resolution. With this method, our group breaks the limitation brought by the clock speed in a circuit, and increases the time resolution of high precision timing generation to pico-second level for the first time. The research results have been published in “Review of Scientific Instruments” (Rev. Sci. Instrum. 89, 7 (2018)) in the form of “Editor’s pick” in July 2.

High precision timing generator has been widely used in instrumentation, measurement, and frontier scientific researches including quantum computation and quantum metrology. Timing generator can generate precise timing pulses to control and synchronize different parts of a system. In the past few decades, most of the timing generators using high-speed clock method to generate the pulse sequences. In high-speed clock method, the time resolution is usually limited by the clock speed. To realize a pico-second resolution timing generator in high-speed clock method, a clock frequency higher than 10 GHz, equivalent to 100 picoseconds, is needed. But circuits running this fast is hard to realize.

In this work, a method called “Time Folding Alignment” is originally developed by Prof. Du’s group. Combined with “Time interpolating” method, the “Time Folding Alignment” can not only break the limitation of time resolution brought by the clock speed to realize a pico-second time resolution, but also can improve the non-linearity of the timing generator on pico-second scale. The test results proves that the newly developed arbitrary timing generator has a time resolution of 5 picoseconds, and the pulse width can be varied over 10 orders of magnitude between 5 nanoseconds and 10 seconds. Besides, the time resolution has the potential to be further improved by “Time Folding Alignment” method, and the method can be used in other fields that need high precision timing generation. The reviewer thinks highly of this work, and comments, “The time folding method is original for timing generator applications and essential to the resolution and nonlinearity-error improvement.” And AIP SCIlight reported this work with the title of “Timing generator breaks clock speed limits in circuits using time folding and interpolating technique.”  

Xi Qin and Wenzhe Zhang are the co-authors of this work.

This work was supported by the NNSFC (Grant Nos. 81788101 and 11227901), the CAS (Grant Nos. GJJSTD20170001 and QYZDY-SSW-SLH004), the National Key R&D Program of China (Grant Nos. 2013CB921800, 2016YFB0501603, and 2018YFA0306600), Anhui Initiative in Quantum Information Technologies (Grant No. AHY050000), and the Fundamental Research Funds for the Central Universities. X.R. thanks the Youth Innovation Promotion Association of Chinese Academy of Sciences for support.