TY - GEN
T1 - Multi-focusing Microlens Array with Different Numerical Aperture by Thermal Reflow Method
AU - Park, Min Kyu
AU - Kim, Hak Rin
AU - Son, Ki Beom
N1 - Publisher Copyright:
© 2014 IEEE.
PY - 2014
Y1 - 2014
N2 - We demonstrate a fabrication method of multi-focusing micro lens array (MLA) through thermal reflow method, and its optical properties. In our multi-focusing MLA, each lens structure was hexagonally packed, and we introduced a partial developing process and a confinement wall structure made by cross-linked photo resist (PR) material to fix a diameter of reflowed spherical lens structure. Due to the base PR layer supporting the thermal reflow process and the guiding structure, the thermally reflowed PR lens structure has different radius of curvatures with different numerical apertures (NAs), where the reflowed PR lens structure could be precisely modeled by the initial volume of the double cylinder PR structure. The multi-focusing MLA we fabricated by using ultraviolet (UV) curable polymer with 1.51 refractive index had four different focal lengths of which values were 0.9 mm, 1.1 mm, 1.6 mm and 2.5 mm, respectively, with four different NAs of which values were 0.1799, 0.2783, 0.3973 and 0.4775, respectively, where the fill factor was 0.7727.
AB - We demonstrate a fabrication method of multi-focusing micro lens array (MLA) through thermal reflow method, and its optical properties. In our multi-focusing MLA, each lens structure was hexagonally packed, and we introduced a partial developing process and a confinement wall structure made by cross-linked photo resist (PR) material to fix a diameter of reflowed spherical lens structure. Due to the base PR layer supporting the thermal reflow process and the guiding structure, the thermally reflowed PR lens structure has different radius of curvatures with different numerical apertures (NAs), where the reflowed PR lens structure could be precisely modeled by the initial volume of the double cylinder PR structure. The multi-focusing MLA we fabricated by using ultraviolet (UV) curable polymer with 1.51 refractive index had four different focal lengths of which values were 0.9 mm, 1.1 mm, 1.6 mm and 2.5 mm, respectively, with four different NAs of which values were 0.1799, 0.2783, 0.3973 and 0.4775, respectively, where the fill factor was 0.7727.
KW - imprinting process
KW - integral imaging
KW - microlens array
KW - multi-focusing lens
KW - thermal reflow process
UR - http://www.scopus.com/inward/record.url?scp=84988222560&partnerID=8YFLogxK
U2 - 10.1109/ISOT.2014.77
DO - 10.1109/ISOT.2014.77
M3 - Conference contribution
AN - SCOPUS:84988222560
T3 - 2014 International Symposium on Optomechatronic Technologies, ISOT 2014
SP - 287
EP - 290
BT - 2014 International Symposium on Optomechatronic Technologies, ISOT 2014
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2014 International Symposium on Optomechatronic Technologies, ISOT 2014
Y2 - 5 November 2014 through 7 November 2014
ER -