Introducing the KTN optical scanner and the KTN variable focus lens. KTN Optical Deflector The KTN optical scanner is a high-speed, compact, non-transmissive optical scanner with no mechanical moving parts. KTN Varifocal Lens The KTN varifocal lens is the world's fastest lens, capable of changing the focal length in microseconds by controlling the voltage applied to the KTN crystal.