Data transmission of the present and future
One of the greatest challenges of the coming years is the exponential increase in data traffic that networks will have to cope with. The use of fibres as optical waveguides play a central role in bridging long distances and has long been a ubiquitous part of everyday life. Domestic fibre optic connections to the Internet are an impressive example of how this technology enables the fast and low-loss transport of large amounts of information over long distances.
However, while fibres are an efficient solution for long-distance connections, bridging shorter distances is a problem that has not yet been adequately solved – especially in local networks and data centres to bridge the interface between the data-transmitting optical fibre and the data-converting electronics.
Innovative manufacturing process: Mosquito method
As part of the 3D-MosquitOPrint research project (funding code 01IF22434N), the Institute of Transport and Automation Technology (ITA), in cooperation with the Laser Zentrum Hannover e.V. (LZH), is therefore investigating a novel process for manufacturing integrated optical waveguides on spatial circuit carriers, so-called 3D-Mechatronic Integrated Devices (3D-MIDs).
Until now, 3D-MIDs have only had conventional electrical conductor paths. The aim of the project is to expand them with optical waveguides. In addition to a higher data throughput, this also enables resistance to electromagnetic interference, which means that additional signal shielding of the connection can be avoided. In addition, optical transmission paths enable galvanic isolation of two circuits, so that they can be used in environments with strong electrical fields and in potentially explosive atmospheres.
Integration of electrical and optical conductors in one component
The innovative Mosquito method is being researched to realise such a hybrid component, which provides both electrical and optical conductor traces. Using a wet-on-wet dispensing process, the method enables the fabrication of circular waveguides.. The light-conducting core is dispensed into a still-liquid optical cladding polymer using a needle. This process is reminiscent of a mosquito bite – hence the name ‘mosquito’. The entire structure is then cured under UV radiation and the interaction of the two liquids results in the round cross-sectional profile of the dispensed structure.
Versatile thanks to sequential application
The sequential dispensing process can be used to realise a wide range of different requirements for the waveguide. By varying the feed rate at which the needle moves through the liquid cladding material and the core material is applied, cores with different diameters can be manufactured. Another parameter for possible modifications is the dispensing pressure with which the material is pressed out of the cartridge.
A new test rig developed at the ITA also allows a wide variety of three-dimensional paths to be traced, so that light inputs and outputs can be connected to each other outside an optical axis via curves. It is also possible to switch flexibly between different core and cladding materials. The process therefore addresses a wide range of challenges in micro-optics and can, for example, be used in the future to realise cross-scale waveguide systems as a interposer between several integrated optical systems.
