Aspheric lenses reduce aberration and provide sharper images with improved spot size compared to spherical lenses. This paper demonstrates that applying shear flow can produce plano‐concave liquid crystal (LC) lens arrays with paraboloid aspheric profiles. The focal length of individual lenses, with a 0.2 mm aperture, decreases from 0.67 to 0.45 mm as the chiral dopant increases from 0 to 6 wt%. The focal length is also sensitive to the polarization state of the incoming light. The lenses are stabilized by photopolymerizing with 6 wt% of reactive monomer added to the LC. A qualitative explanation for the flow‐induced lens formation and the optical properties of the lenses is provided. The potential tunability of the lenses in various fields and their use as paraboloid reflectors are discussed.
Optofluidic devices that dynamically respond to light stimuli have the potential to impart modern adaptive optics with intrinsic optical logic without the need for external power sources or feedback control. While photo actuation is typically associated with low energy efficiency compared with alternative modes of actuation, fluid lenses can be tuned with minimal work by generating small differential pressures across the surface of the lens to drive a change in focal length. In this study, we developed a wide aperture (9.5 mm) photothermally actuated lens that leverages spatially and thermodynamically informed design principles developed for resistively heated thermo-pneumatically actuated lenses. Using experimentally validated models to describe the curvature of pressurized elastomer-bound interfaces, we demonstrated phototunable modulation of the focal length from 124 mm to 90 mm in real time using 233 mW of 405 nm light over 30 s of irradiation with an estimated 8.2 µJ of mechanical work (10−4% efficiency). The initial focal length recovered after 60 s in the dark over three consecutive cycles of actuation. Additionally, the photoactuated response is shown to correlate well with the light intensity.
more » « less- PAR ID:
- 10521872
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 32
- Issue:
- 15
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 26445
- Size(s):
- Article No. 26445
- Sponsoring Org:
- National Science Foundation
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