Free-space optical communication link with modulator-detector integrated arrays

Background

Optical free-space communication systems are today commercially available as fixed point-to-point communication links. Optical free-space links offer advantages in terms of bandwidth (up to 10 Gb/s), security (jamming and eavedropping) and flexibility (no license required) compared to RF links. They also provide cheaper, faster-to-install and more flexible solutions than optical fibre links.
Recently, further developments of this concept to mobile users have been proposed by several research groups ,based on retromodulation utilising a corner cube and a fast light modulator at the mobile unit. Earlier demonstrators were based on liquid crystal modulators, but semiconductor modulators are required to implement broadband optical communication links between mobile users.
In this study, surface-normal electroabsorption modulators will be investigated and experimentally evaluated as dual-finction devices, e.g. capable of both modulating and detecting light.

Goal

To experimentally demonstrate the benefits of integrated arrays of modulators and detectors for broadband free-space optical communication.

Description

The following tasks will be conducted in the frame of the diploma work project, with a strong emphasis on task 3:

1. Modelling of a pixel element as modulator and detector
2. Design of drive electronics.
3. Experimental characterisation of a pixel element as modulator and detector.
4. Test in a communication link

Note: 1-D array (64 pixels) devices that have been successfully developed in the frame of a current Europan project will be used for this task.