NTT have developed a variable focus lens that they claim is 1,000x faster than existing technology. The lens is based on KTN (potassium tantalate niobate), an “electro-optic crystal” the refractive indices of which varies depending on how much voltage is applied across its surface. By adjusting the voltage, the focal length varies.
Existing variable focus lenses using piezoelectric zirconate titanate (PZT) are one thousand times slower, according to NTT. This new lens can be combined with a KTN-based optical beam scanner for 3D photography.
In its current state the KTN lens is unlikely to find its way into many cameras, though. It requires careful temperature management – at the wrong temperature it goes opaque, not much use for a camera lens – which right now demands the Peltier setup shown above. NTT have not given a timescale for commercialization of the technology.