Focus Tunable Lenses

Adaptive polymer based optics can provide a smart, low-cost, yet high-quality alternative to traditional optics. Using a liquid polymer, Optotune has developed a range of focus tunable lenses - offering freedom and flexibility to optics designers and a fast response time of just a few milliseconds.

A change in lens radius of several micrometers can have the same optical effect as moving the entire lens several centimeters. By using focus variable lenses, optical systems can thus be designed to be more compact, often with fewer lenses, and usually with less or no translational movement meaning no more need for expensive mechanical actuators. Less movement also leads to a more robust design, which can be completely closed so that no dust can enter.

Electrically focus tunable lenses can be used for fast control of the z-position of the laser spot in laser scanners and 3D laser processing, resulting in a more compact, reliable and less expensive system.

The materials employed for these adaptive lenses are all lighter than glass, saving overall weight. Less movement and weight also means less power consumption and faster response times, in the order of milliseconds.

Fast change of Z-position due to response time of just a few milliseconds


The curvature of this shape changing polymer lens is adjusted by applying current. The focal length is accordingly tuned to a desired value within milliseconds. Optotune offers three different types of housings of the EL-10-30. The compact 30x10.7 mm housing, a 30x20 mm housing with C-mount threads and the Industrial C-mount housing (Ci) with Hirose connector. For each housing there are different options to adapt the lens to your needs.


The EL-10-42-OF has an integrated optical feedback, measuring the optical power of the lens in real-time. Optimal control is guaranteed in combination with the EL-E-OF-A electronics. As a consequence, reproducibility and focus stability is extremely high which makes Optotune’s EL-10-42-OF the perfect choice for laser processing applications.


By applying an electric current to this shape changing polymer lens, its optical power is controlled within milliseconds over a diopter range of -2 dpt to +3 dpt. A major hallmark of this shape changing lens is the clear aperture of 16 mm. In order to achieve good repeatability and focus stability, Optotune integrated a temperature sensor allowing for in-situ compensation of temperature effects. The lenses are therefore ideally suited for a large variety of applications where imaging and a large beam diameter is of importance.

Fast Electrically Tunable Lens EL-3-10

The compact EL-3-10 lens is 10x4 mm with a clear aperture of 3mm, and was designed for OEM integration into optical systems. The curvature of the lens is adjusted by applying an electrical current, and the focal length is tuned to a desired value within very few milliseconds. The lens architecture is “push pull” which means that the lens curvature is deflected from concave to convex. With actuators based on proven voice-coil technology, the EL-3-10 focus tunable lens is extremely reliable and robust, well suited even for applications in harsh environments over large temperature ranges.

Lens Driver 4

The Lens Driver 4 offers a simple yet precise way to control Optotune’s electrically tunable lenses, in particular the EL-3-10, EL-10-30 and EL-16-40 series. 

Communication with the driver follows an open simple serial protocol, which can be implemented in any programming language on Windows or Linux (C#, Labview and Python source code available). The driver comes with free software and can be used as a standalone solution or integrated into OEM designs. As a compact USB-powered current source, it also serves for driving LEDs or laser diodes.


The Optotune ML-20-37 manually tunable lens is designed to have its lens curvature change between convex (+18 dpt), flat (0 dpt), and concave (-18dpt) by the rotation of the outer adjustment ring. This allows for the focal length of the lens to be tuned to the precise value required for an optical application. The rotation mechanism is extremely durable (>100'000 rotations), low torque and linear.

ML-20-37 is available with and without C-mount adapter.

Laser Processing Application Note Application note for laser processing using EL-10-42-OF tunable lens and SCAPS Optotune-DSD driver board
OCT Ophthalmology Application Note Fast focusing for high resolution optical coherence tomography with Optotune products