High
Numerical Aperture Hexagonal Stacked Ring-Based
Bidirectional Flexible Polymer Microlens Array
Rajib Ahmed
Ali K. Yetisen
Haider Butt
10.1021/acsnano.7b00211.s001
https://acs.figshare.com/articles/journal_contribution/High_Numerical_Aperture_Hexagonal_Stacked_Ring-Based_Bidirectional_Flexible_Polymer_Microlens_Array/4718917
Flexible
imprinted photonic nanostructures that are able to diffract/focus
narrow-band light have potential applications in optical lenses, filters,
tunable lasers, displays, and biosensing. Nanophotonic structures
through holography and roll-to-roll printing may reduce fabrication
complexities and expenses and enable mass production. Here, 3D photonic
nanostructures of a stacked ring array were imprinted on acrylate
polymer (AP) over poly(ethylene terephthalate) (PET) substrate through
holography and lift-off processes to create a microlens array (MLA).
The surface structure of the array consisted of circular nonostepped
pyramids, and repeated patterns were in hexagonal arrangements. Stacked-ring-based
MLA (SMLA) on a flexible AP–PET substrate showed efficient
bidirectional light focusing and maximum numerical aperture (NA =
0.60) with a reasonable filling factor. The nanostructures produced
a well-ordered hexagonally focused diffraction pattern in the far
field, and power intensities were measured through angle-resolved
experiments. The variation of nanostep dimensions (width and height)
and the number of steps resulted in different photonic bandgaps, and
the arrays produced distance-dependent narrow-band light focusing.
The validation of the SMLA was demonstrated through the text, image,
and hologram projection experiments. It is anticipated that imprinted
bidirectional SMLA over flexible substrates may find applications
in optical systems, displays, and portable sensors.
2017-03-02 19:34:51
microlens array
distance-dependent narrow-band light
angle-resolved experiments
substrate
diffraction pattern
mass production
holography
Polymer Microlens Array
well-ordered hexagonally
Ring-Based Bidirectional
power intensities
acrylate polymer
ring array
nonostepped pyramids
3 D photonic nanostructures
photonic bandgaps
NA
hologram projection experiments
photonic nanostructures
roll-to-roll printing
bidirectional SMLA
display
High Numerical Aperture Hexagonal
tunable lasers
lift-off processes
Nanophotonic structures
application
bidirectional light
AP
nanostep dimensions
fabrication complexities
surface structure
Stacked-ring-based MLA