28
J. Eur. Opt. Society-Rapid Publ. 22, 3( 2026)
Figure
3.( a),( b) and( c) show the target irradiance, obtained mapping functions m and extracted non-sequential irradiance distribution, respectively, associated with the freeform surface generated for the cosine-squared case( u ff shown in Fig. 2a). Similarly, in( d),( e) and( f) the results associated with the uniform target case are presented.
Figure 4.( a) and( b) present fit residue maps DS z obtained after using least squares projections based on Forbes Q freeform polynomials to represent both FEM solutions.( c) presents power spectral density( PSD) cross-sections extracted from both residue maps shown in( a) and( b).( d) provides a comparison between DS z RMS curves as a function of the expansion index T.