Hartmann-shack Wavefront Sensor In The Beam Quality Diagnostic Studies,

The system of far field diagnosis is the system that we usually use in detecting the far field of laser beam. When it is used in detecting the far field of laser beam ,the method is simple, and the result is easily seen. So, it was used widely in many application.Because the element of the far field diagnosis system which is used to detecte facula is CCD, when it works, much types of noise will affect it, and threshold value will affect the efficient signal. In this paper, Hartmann-Shack wavefront sensor which can detect the phase of beam is studied, what is detected by Hartmann-Shack wavefront sensor can be transform into far field, and we compare this result with that detected by the far field diagnosis system, and we can know which system is more accurate. In fact, Hartmann-Shack wavefront sensor is affected by the noise of CCD and the constructed error too.In our compare, a bridge is setup, which is the original wavefront composed by Zernike polynomial, we transform the original wavefront into far field. Then we can compare the accuracy of Hartmann-Shack wavefront sensor with the accuracy of the system of far field diagnosis in detecting the farfield, using diffraction limit and encircle energy.In this paper, we get the result that the accuracy of Hartmann-Shack wavefront sensor used in detecting far field is better than that of the system of far field. And we simulate the thing by different spatial frequency Hartmann-Shack wavefront sensor which is used in detecting the far field of laser beam, and we get the result that if magnitude of wave aberration is lower the dynamic range of sub-aperture of wavefront sensor, the more the spatial frequency of Hartmann-Shack wavefront sensor is, the more the accuracy of Hartmann-Shack wavefront sensor in detecting high frequency aberration is.