[Abstract] This video introduces a novel variable focus lens with a large optical aperture of 26 mm. As far as we are aware, compared with liquid-air lenses and liquid-liquid lenses, our lens with such a large aperture that can also achieve high optical performance is the first of its kind.
[Background] To realize focus shifting with traditional solid lenses, two or more lenses have to cooperate with each other. Instead of moving the solid lenses mechanically to change the focal length, a variable focus lens can dynamically control its focal length by using a single lens cell.
[Solution] The system is based on a sandwiched structure. A piece of deformable elastomer separates the system into two chambers. These chambers are infused with two different fluids. If one fluid can be made to flow into and out of its chamber, the lens can shift its power dynamically by means of a syringe pump. Based on this concept, a prototype of a variable focus lens with a 26 mm aperture was fabricated. However, there is no technical challenge involved in making the aperture even larger.
Ishikawa Watanabe Laboratory: http://www.k2.t.u-tokyo.ac....
Oku Laboratory: http://okulab.wix.com/okulab-e
Applied Physics Letters, Vol.102, 131111 (2013); http://dx.doi.org/10.1063/1...
Optics Express, Vol.22, Issue 16, pp. 19448-19456 (2014); http://dx.doi.org/10.1364/O...