Optotune focus tunable liquid lenses provide a versatile, compact and cost-effective solution to overcome this challenge. Thanks to the absence of translational mechanics, liquid lenses have the possibility to focus within few milliseconds combining coarse and fine focusing range, ensuring no vibration and reliability with a lifetime of billions of cycles.

A particularly interesting use case is using liquid lenses for z-stacking, to acquire 3D information (DFF) or to compute images with extended depth of field (EDOF).

Applications    

• Wide-field microscopy

• Confocal Microscopy

• 3D Light Sheet microscopy

• Spectroscopy

• Digital holographic Microscopy

Advantages

• Fast Z stacking

• No vibrations

• Large working distance range

• No chromatic aberrations

• Long Life-time (>1B cycles)

Where to integrate the liquid lens

Non-telecentric configuration

The most straight-forward integration of a liquid lens in a microscopy system is to place it right above the objective lens, which is especially practical for infinity corrected objective lenses. The advantage of this configuration is that very large Z-ranges are achievable. For example, at a magnification of 40x a liquid lens with 5 diopters of tuning range will result in a working distance range of about 160µm. There is a magnification change across the Z-range, which is linear and reproducible.

Telecentric configuration without magnification change

Microscopy systems where magnification change is undesirable require a configuration where the liquid lens does not affect the magnification. This is possible by placing it inside a system of relay lenses at a conjugate pupil position. The achievable Z-range is generally smaller as in the non-telecentric configuration.