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KTN Varifocal Lens

The world's fastest lens that can change focal length in microseconds

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Two-photon imaging of C. elegans

The KTN varifocal lensis the world's fastest lens, capable of changing the focal length in microsecondsby controlling the voltage applied to the KTN crystal.

This is 100 times faster than conventional variable focus lenses.

* The above micrograph is a two-photon image of C. elegans. This image was kindly provided by Prof. Junichi Nakai and Dr. Keiko Ando, Tohoku University. All neurons expressed GFP. The two micrographs were taken at different imaging depths.

KTN variable focus lens: Focus adjustment mechanism and performance

Conceptual diagram

KTN variable focus lens conceptual diagram
KTN variable focus lens conceptual diagram

Focal length shift performance

KTN variable focus lenses act as convex lenses, with focal length varying in proportion to the square of the applied voltage. Typical results for lens power using practical dielectric constants are 1.0 m-1 when 1 kV is applied.*

* Source: APPLIED OPTICS Vol. 51, No. 10 1 April 2012, APEX-4-022501.

Relationship between voltage and focal length Δf
Relationship between voltage and focal length Δf
Time Response
Time Response

Application example

3D Microscope Equipment


Case Study

Biological microscope
Example: Supporting 3D live cell analysis with nanometer-level resolution
  1. Klaus C. Gwosch, Jasmin K. Pape, Francisco Balzarotti, Philipp Hoess, Jan Ellenberg, Jonas Ries and Stefan W. Hell “MINFLUX nanoscopy delivers 3D multicolor nanometer resolution in cells”, Nature Methods, volume 17, 217–224, 2020.
  2. Jasmin K. Pape, Till Stephan, Francisco Balzarotti, Rebecca Büchner, Felix Lange, Dietmar Riedel, Stefan Jakobs and Stefan W. Hell, “Multicolor 3D MINFLUX nanoscopy of mitochondrial MICOS proteins”, Proc. Natl. Acad. Sci. USA, published August 11, 2020.
3D measurement with KTN scanner


Lens Power 0 - 0.5m-1
Driving Frequency DC - 10kHz
Wavelength 488 - 3500nm
Output Beam Diameter 3 mmφ
Size 97 x 85 x 32 mm

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KTN Varifocal Lens module  

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