In order to achieve high measuring resolution in wide measuring range with laser heterodyne interferometry measurement in nanometer level

a novel integer-fraction combined signals processing method is presented.Both traditional phase measuring method for inner-period measurement and frequency multiply counting method based on phase locked loop for integer periods measurement are used.The integer phase is obtained by eliminating opposite pulses and alternate pulses

and the fraction phase is obtained using phase demodulation method of high resolution

then combine them correctly.The experimental comparison and analyses indicate that resolution of distance-measurement 10 nm

the difference less than 0.09 μm in the range of 1.2 m comparing with HP5528

the static phase resolution of 0.011°and the static resolution better than 0.1 nm can be achieved in laser heterodyne interferometry measuring system using the proposed method

and this method is also an effective way in displacement measurement with wide measuring range and high measuring resolution.