Germany has developed direct laser welding technology to achieve adhesive free connection from fiber to chip

Recently, researchers and their partners from the Fraunhofer Institute for Reliability and Microstructure (IZM) in Germany announced the successful development of a laser welding technology that can efficiently fix optical fibers onto photonic integrated circuits (PICs) without the need for adhesive bonding.

This technology is developed in response to biophoton sensing technology, mainly utilizing a miniaturized photonic integrated circuit (PIC) system with highly stable fiber connections.

(Image source: Fraunhofer IZM)
In the past, adhesive was often used in fiber optic interconnections of photonic integrated circuits. However, in the long run, this solution will lead to the occurrence of optical degradation, ultimately resulting in optical transmission loss. The softness of the adhesive can cause the position of the component to change over time and create an interference point between the two layers of glass. As the adhesive ages, this can lead to signal attenuation and brittle connections.

Due to the different volumes of glass fiber and substrate, the heat capacity of the two parts to be joined is not equal, resulting in different heating and cooling behaviors. If there is no appropriate compensation for the difference, it may lead to deformation and cracks during the cooling process. To address this issue, the team used a separate adjustable laser to uniformly preheat the substrate, allowing the melting stage of the fiber and substrate to occur simultaneously.

The technology developed by this project is no longer limited to the experimental setup stage, and the system they developed is designed for industrial environments. The Fraunhofer Institute for Reliability and Microstructure (IZM) in Germany, in collaboration with Finicontec Service, implemented this technology process in automation systems and found that it has high repeatability and scalability. It is equipped with thermal process monitoring up to 1300 ℃, accurate to 1 μ M's positioning system, as well as imaging recognition process and control software.

The potential of high automation enables customers to use photonic integrated circuits (PICs) with maximum coupling efficiency. Industrial integration means a leap in the field of biophotonics applications, as well as quantum communication and high-performance photonics, "G ó mez said.

Source: OFweek