Translational offset detection based on far-field intensity for grating tiling

The far-field intensity is detected from far-field image to estimate the piston distance between two gratings. The image processing algorithm includes projections along the horizontal and vertical directions, search for each focal spot's centre, feature extraction and intensity computation. Each focal spot's centre can be found with the projections. A self-growing method is used for feature extraction, where the threshold value depends on the gray value of each focal spot's centre. For each focal spot, the sum of gray values within the relevant domain is taken to be its energy intensity. Furthermore, the energy ratio of left and main focal spots (or main and right focal spots) is computed. A formula that expresses the piston distance between two gratings as the function of the energy ratio is fitted with several measured points. Based on this formula, the piston distance is obtained for a new energy-ratio. Finally, the proposed method is verified with a series of experiments.

[1]  Lijiang Zeng,et al.  Method to mosaic gratings that relies on analysis of far-field intensity patterns in two wavelengths , 2007 .

[2]  Wang Yong and Liu Zhigang and Bo Feng and朱健强.  DESIGN AND CONTROL OF AN ULTRAPRECISION STAGE USED IN GRATING TILING , 2007 .

[3]  Joachim Bunkenburg,et al.  Demonstration of coherent addition of multiple gratings for high-energy chirped-pulse-amplified lasers. , 2004, Optics letters.

[4]  Igor Jovanovic,et al.  Diffraction grating eigenvector for translational and rotational motion. , 2006, Optics letters.

[5]  Tao Wang,et al.  Object-image-grating self-tiling to achieve and maintain stable, near-ideal tiled grating conditions. , 2010, Optics letters.

[6]  A. Cotel,et al.  Phased-array grating compression for high-energy chirped pulse amplification lasers , 2006, 2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference.

[7]  M. Guardalben.  Littrow angle method to remove alignment errors in grating pulse compressors. , 2008, Applied optics.

[9]  Yoshiaki Kato,et al.  An array-grating compressor for high-power chirped-pulse amplification lasers (Optics Comm. 145 (1998) 367) , 1998 .

[10]  Yanlei Zuo,et al.  Eliminating the longitudinal piston error between tiled gratings by angle tuning. , 2007, Optics letters.

[11]  Fu Hong-ya.  Design method of controlling device for tiling high pecision and large aperture grating , 2009 .

[12]  Hao De-fu.  Manufacturing large-size grating by mosaic way , 2000 .

[13]  W. Skulski,et al.  Phase-locked control of tiled-grating assemblies for chirped-pulse-amplified lasers using a Mach-Zehnder interferometer. , 2006, Optics letters.

[14]  J. Kelly,et al.  Large-aperture grating tiling by interferometry for petawatt chirped-pulse-amplification systems. , 2007, Optics express.