Batch production of birefringent dual frequency laser interferometer in China

On March 2, we learned from the Department of precision instruments of Tsinghua University that Professor Zhang Shulian's research group of the Department has carried out the principle research, and the birefringence dual frequency laser interferometer developed and produced by Beijing radium Measurement Technology Co., Ltd. has realized mass production.
Dual frequency (two frequency) laser interferometer is an optical ruler for scientific research, lithography, CNC machine tools, aerospace, ships and other industries. It is used to measure the size, angle, position and linearity of parts. It is also a basic instrument for verifying the accuracy of various CNC machine tools, laser processing machine tools and lithography machines and for error compensation.
Zhang Shulian introduced that dual frequency laser is the core component of dual frequency laser interferometer. Foreign interferometer manufacturers are self-made special laser, known as Zeeman dual frequency laser, not for external supply. In the past, China's dual frequency laser interferometer could only import ordinary lasers, from which the usable ones were selected, with high elimination rate and poor performance, leading to difficulties in localization of dual frequency laser interferometer.
According to reports, the birefringent dual frequency laser invented by the Department of precision instruments of Tsinghua University is twice as high as the traditional Zeeman dual frequency laser in laser power, twice or three times as large in frequency interval, and there is no coupling and mixing between two frequencies. The resolution is 1 nm (billionth of a meter), the linear measurement length ranges from 0 to 70 meters, the nonlinear error is less than 1 nm, and the measurement speed is more than 2 meters.
Zhang Shulian pointed out that the use of birefringent dual frequency laser has led to the innovative design of the optical mechanical and electrical system of the interferometer, making the birefringent dual frequency laser interferometer portable, convenient, robust and other excellent performance.