The morning sessions of the third Symposium day concentrated further on the technology of microoptics. Pierre Craen (poLight, Norway) gave a talk about a new auto-focusing system for mobile phone applications. The technology is MEMS based : a polymer is sandwiched between two glass surfaces. The lower one is a rigid glass plate, the top one is a glass membrane which is deformable through a piezofilm (driven at 20V). The deformation of the glass membrane is transformed into the polymer and in this way a deformable lens can be created (looks a bit similar to the fluid lens of Varioptic, but now with glass and polymer instead of water and oil).
During the presentation several measurements and data were shown. What I could grab : 1 ms reaction time, 5 mW power consumption, very small, very thin (0.4 mm thickness), transmission > 95 %, diffraction limited, re-flowable at 260 deg.C, wafer scale technology (8”) and a wide temperature range (- 40 deg.C to 200 deg.C). Also mentioned was the limitation of the technology to small apertures (up to 1.7 mm, corresponding to maximum 1/3” or 1/2.5” image sensors). The technology is named : Tunable Lens or TLens.
Is this technology capable of kicking the VCMs ou of the mobile phones ? According to Eric Mounier (Yole Developpement, France) VCMs still have 95 % market share. Nice opportunity for poLight, but also nice challenge for the TLens.