Two novel applications of laser frequency splitting technology are reported, including two methods in solving the problem of mode competition to obtain a dual frequency laser whose frequency difference can cover 1-40 MHz, as well as the principle and the experiments of making a birefringence dual frequency laser itself be a displacement sensor.

A temperature control system of LD-pumped single-frequency laser.

The principle of monolithic nonplanar ring single-frequency laser was introduced, and eigenpolarization states of monolithic unidirectional traveling wave nonplanar ring oscillator (NPRO) were calculated by Jones matrix.

When a dual-frequency laser is used as the light source of the ADI system, it requires that the synthetic wavelength be as small as possible, namely, the frequency-difference be as large as possible so as to improve the measurement accuracy.

Because this measurement approach measures the distance rather than the displacement, it doesn’t need precise guide rail, but in order to improve the accuracy of absolute-distance measurement, smaller synthetic wavelength is required, which can be obtained by use of a dual-frequency laser source with its frequency-difference as large as possible.

The dual-frequency laser as a light source takes a key element in the interferometer.