Performance of the gravity-compensated liquid lenses

In two previous blog posts, we explained the coma aberration effect that gravity introduced on the standard liquid lenses from Optotune and how it has been solved in the latest generation of the lenses.

Those two blogs treated the topic only from a theoretical perspective, but they did not show any data.

Fixing the gravity coma dominated wavefront error

When used in vertical axis configuration, the wavefront error (WFE) of Optotune’s standard liquid lenses is comparable to that of traditional optics. Unfortunately, when those lenses are rotated the coma aberration generated by the weight of the optical liquid pushing on the flexible membrane grows until dominating the WFE. This aberrations render the lenses unsuitable for those applications that need the best optical performance.

As the plot below shows, the new generation of lenses featuring Optotune’s patented gravity coma compensation eliminates this effect completely, regardless of the orientation in which the lens is used. This technology had been proven and tested in prototypes before, but only within the iToBoS project Optotune was able to implement it in a full lens, ready to be used in the field. The chosen liquid lens is EL-16-40-TC, which has been upgraded to a new gravity-compensated model, the EL-16-40-GTC.

Figure 1. Coma component of the wavefront error of EL-16-40 lenses without and with the gravity compensation technology.