Recently, the femtosecond optical comb and its application research group led by the National Time Service Center Zhang Shougang and Jiang Haifeng researchers have made important progress in the research of ultra-stable laser pointer, and its related technical indicators have reached international advanced levels.
The team used self-designed and developed electro-optic modulators to greatly reduce the residual amplitude modulation noise in the commonly used laser PDH frequency-locking technology, and successfully locked the frequency of the 1555 nanometer fiber laser at the resonance of the ultra-low expansion coefficient glass (ULE) optical reference cavity Frequency. By comparing two sets of ultra-stable laser systems in different laboratories, the line width of the ultra-stable laser beat frequency is 185mHz, and the short-term frequency stability reaches 7 × 10-16. The result will be published in Chinese Physics letters in September this year The experimental results of its electro-optic modulator were published in the Optics Letters of the American Optical Society, and have applied for PCT international patent “PCT / CN2016 / 070552” and US patents.
The ultra-stablegreen laser pointer has important applications in the fields of optical frequency standards, ultra-stable microwave sources, ultra-precision spectroscopy, and gravitational wave detection, and is one of the competitive focuses of international precision metrology research. At present, the ultra-stable laser system developed by the team has been successfully applied to the ultra-stable photo-generated microwave development project, and will also provide favorable support for the development of optical clock system, reference fountain clock development, fiber frequency transmission and other projects undertaken by the National Time Service Center.