[1] G Sehulz, J Sehwider. Precise measurement of plainness[J]. Appl Opt, 1967, 6(6): 1077-1084.

[2] G Sehulz, J Schwider. Establishing an optical flatness standard[J]. Appl Opt, 1971, 10(4): 929-934.

[3] M Vannoni, G Molesini. Absolute planarity with three-flat test: an iterative approach with Zernike polynomials[J]. Opt Express, 2008, 16(1): 340-354.

[4] Xu Chen, Chen Lei. Absolute flatness measurement of optical surfaces[J]. Optical Technique, 2006, 32(5): 775-778.

[5] Michael F Küchel. A new approach to solve the three-flat problem[J]. Optik, 2001, 112(9): 381-391.

[6] R Schreiner, J Schwider, N Linidlein. Absolute testing of the reference surface of a Fizeau interferometer through even/odd decompositions[J]. Appl Opt, 2008, 47(32): 6134-6141.

[7] Liu Xiaomei. Absolute Measurement of Optical Flat[D]. Nanjing: Nanjing University of Science & Technology, 2004.