Project title:                     Switchable diffractive liquid crystal lens

Task:

To design and build a dynamic diffractive optical element (DOE) based on a pixilated liquid crystal (LC) device.

Short description of device:

In liquid crystal (LC) electrooptic devices the liquid crystal is confined between two substrates, usually glass, and the orientation of the liquid crystal is controlled by means of applied external electric fields. The reorientation of the anisotropic LC gives a change of the optical properties which can be used for amplitude modulation (using linear polarizers) or phase modulation of polarized light.

In this project the student should design and manufacture an LC device component constituting an electrically controlled binary zone plate based on switching of LCs where the zones of the plate are defined by the transparent indium tin oxide electrodes in the device cell. The device is a diffractive focusing lens which can be switched on and off by controlling the effective refractive index of the LC materials with the electric field.

Processes:

Design of lithography mask for zone plate electrode configuration, photolithography, deposition of surface alignment layers for LC alignment, buffing of these alignment layers, LC cell assembly and LC filling.

Characterization:
Microscopy of electrode patterns, electrooptic characterization of manufactured device, optimization of device performance.

Number of students:            2 or 3

Contact:
Sheila Galt  <sheila.galt -et- mc2.chalmers.se>
Per Rudquist <per.rudquist -et- mc2.chalmers.se>