1. Date of download: 7/2/2016 Copyright © 2016 SPIE. All rights reserved. The schematic of experimental setup used for generation of collimated hollow beam of variable diameter. \documentclass[12pt]{minimal}\begin{document}$AX_1$\end{document}AX1 : convex axicon mirror; \documentclass[12pt]{minimal}\begin{document}$AX_2$\end{document}AX2 : concave axicon mirror; γ : cone base angle of each axicon mirror; d: separation between axicon mirrors; PBS: polarizing beamsplitter; λ /4: quarter wave-plate; HB: generated hollow beam; S: screen; z : distance between PBS and screen. Figure Legend: From: Generation of a variable-diameter collimated hollow laser beam using metal axicon mirrors Opt. Eng. 2011;50(1):014001-014001-4. doi:10.1117/1.3530080

2. Date of download: 7/2/2016 Copyright © 2016 SPIE. All rights reserved. CCD images and corresponding intensity profiles of the generated hollow beam at different values of z, for a fixed separation (d = 70 mm) between axicon mirrors. Figure Legend: From: Generation of a variable-diameter collimated hollow laser beam using metal axicon mirrors Opt. Eng. 2011;50(1):014001-014001-4. doi:10.1117/1.3530080

3. Date of download: 7/2/2016 Copyright © 2016 SPIE. All rights reserved. CCD images and corresponding intensity profiles of zeroth order Bessel beams obtained after focusing of diverging (a) and collimated (b) hollow beams. Figure Legend: From: Generation of a variable-diameter collimated hollow laser beam using metal axicon mirrors Opt. Eng. 2011;50(1):014001-014001-4. doi:10.1117/1.3530080

4. Date of download: 7/2/2016 Copyright © 2016 SPIE. All rights reserved. Variation of dark diameter (filled circles) with separation (d). The inset illustrates the measurement of dark diameter from the recorded intensity profile of the hollow beam. The straight line shows ϕ [= 2d tan(2γ)] values. Figure Legend: From: Generation of a variable-diameter collimated hollow laser beam using metal axicon mirrors Opt. Eng. 2011;50(1):014001-014001-4. doi:10.1117/1.3530080

5. Date of download: 7/2/2016 Copyright © 2016 SPIE. All rights reserved. Observed CCD images and corresponding intensity profiles of the generated beam at z = 410 mm for different values of separation (d) between axicon mirrors. Figure Legend: From: Generation of a variable-diameter collimated hollow laser beam using metal axicon mirrors Opt. Eng. 2011;50(1):014001-014001-4. doi:10.1117/1.3530080