Multi-planar imaging using the thermal lensing effect.

The application of a thermal lens, formed by a laser beam, in the imaging of objects lying in three different planes is reported for the first time, to the best of our knowledge. The objects' planes are separated by a distance surpassing the depth-of-field of the imaging setup. It is the local formation of two thermal lenses near the intermediate image plane in a thermo-optical material that allows for the observation of two additional objects. (C) 2019 Optical Society of America