PolyBoard- and SiN-platforms

The Fraunhofer HHI platforms enable the hybrid integration of active and passive optical components in photonic integrated circuits (PICs) in the visible and infrared wavelength range. The micro-optical-bench of the PolyBoard platform facilitates PICs with spectral filters, optical isolators and circulators, as well as nonlinear crystals for applications in quantum optics, among others. The silicon-nitride-platform features highly integrated optical gratings, switches and ring resonators for communications, sensing and medical technology.

A compact RF PIC assembly for fast and convenient prototype development up to 40 GHz

RFconnect, Fraunhofer HHI’s new fiber coupled RF PIC assembly, states a compatible expansion of the already established DC multisource PIConnect. The thermally controllable assembly with 8 RF & optical ports and 42 DC ports facilitates the connection of RF measurement equipment.

High-data rate wireless links at (sub-)THz carrier frequencies

Based on its mature InP technology, Fraunhofer HHI develops photonic components and systems for high-data rate wireless terahertz communications. These components allow for seamless integration into state-of-the-art fiber-based communication systems. Thus, complex modulation formats, such as 32QAM, 64QAM and QPSK, can be used. In a recent publication, we showed up to 160 Gbit/s at 300 GHz carrier frequency using 32QAM (Nellen et al., JLT 40(13), 2022).

Broadband spectral coverage from 100 GHz to 4.5 THz

The photonic terahertz components and systems developed by Fraunhofer HHI are well suited for test and measurement applications for 6G and beyond. In contrast to electronic mixer circuits, with a single system the photonic approach allows for broadband access to frequencies between 100 GHz and 4.5 THz. For example, our cw-THz system T-Sweeper offers up to 50 spectra / s with >4 THz bandwidth or up to 500 spectra / s with 200 GHz bandwidth. Since the specific frequency bands of future wireless communication channels are still a topic of debate, our approach helps to reduce this uncertainty by providing access to a broad spectral range.

Components for 1Tb/s Transmission and Microwave Photonics

Fraunhofer HHI provides single and balanced photodetector modules  with a bandwidth up to 145 GHz operating from the O- to the L-band. The intended application for the modules is high-speed test and measurement. Our novel module design provides higher and smother RF performance and improved reliability.

O-, C and L-band lasers

Fraunhofer HHI develops 100mW DFBs, SOAs and Gain Chips, 200G EMLs and 72G DMLs for hybrid integration with passive PICs based on Silicon on Insulator (SOI), Silicon-Nitride (SiN), Glass (silica), polymer, and LNOI.

Quantum Key Distribution (QKD) enables future-proof long-term protection of sensitive data and communication applications – even against the imminent security threats of quantum computers. Fraunhofer HHI developed a high-speed QKD system that seamlessly integrates in telecom network infrastructures.

A versatile measurement device for digitizing events in time domain with a resolution down to 100 picoseconds 

The Timetagger, developed by Fraunhofer HHI, is a device that digitizes events in the time domain with a resolution of 100 picoseconds. It offers multiple input channels, each with customizable switching thresholds and hysteresis settings. The digitized events can be conveniently accessed through a network interface. The Timetagger is available in two options: as a compact standalone device or as a module that can be easily integrated into FPGA-based systems via the FMC interface.

Coherent optical transport at highest speeds and widest bandwidths

To cope with the continuously growing demand for bandwidth in telecom and datacom, Fraunhofer HHI researchers developed a Coherent Receiver Frontend  (CRF), offering 100 GHz optical bandwidth detection with polarization- and phase-diversity over C+L-band. Its unique features are customizable optical extender heads with robust 1mm RF ruggedized connectors for high signal integrity, robust testing & measurement performance and convenient handling & operation for our customers.

Fraunhofer presents a compact 400G I/Q transmitter and coherent receiver for high-bitrate transmission experiments

Compact optical transceiver to demonstrate high-bitrate data transmission. The transceiver allows for flexible generation and detection of optical data signals up to 64 GBaud. This corresponds to 400 Gbit/s using PDM-16QAM modulation. Several transceivers can be combined in one chassis to realize a multi-channel system.

Fraunhofer HHI and ID Photonics offer a fully integrated Coherent Optical Reference Receiver with up to 60 GHz

The latest Test & Measurement Equipment launched by Fraunhofer HHI and ID Photonics is the fully integrated Coherent Optical Reference Receiver. It comprises a high-bandwidth coherent receiver with transimpedance amplifiers to convert various optical modulation formats (e.g. QPSK and m-QAM) into electrical RF baseband signals with an o/e bandwidth up to 60 GHz into. Its unique features are a high fidelity tuneable C-band laser source and a fully integrated Coherent Optical Reference, enabling symbol rates beyond 120 GBaud/s in the Terabit/s single carrier regime.

At Fraunhofer HHI, we show neuromorphic computing using reservoir architecture for use-cases such as smart monitoring of state-of-the-art optical modulation formats. Our 4mm-by-7mm SOI-based photonic integrated circuit hardware can predict modulation formats after 100 km transmission with an accuracy of more than 97%.

Passive Optical Networks for the Indoor Fronthaul of high data rate LiFi Systems

Fraunhofer HHI presents a modular LiFi system that can also be connected via fiber-to-the-room for the first time. The optical access points can be connected to a passive optical network (XGS-PON) and thus enable high data rates and a low-latency connection. In addition, the high capacity of the PON makes it a sustainable and future-proof building network.

Machine Learning as a Service for Optical Network Automation

We demonstrate the benefits of a Federated Learning framework for collaborative training of ML-assisted solutions for multi-domain multi-vendor ecosystems. The demonstration showcases the recent addition of the framework, Differential Privacy, which protect the privacy of the parties contributing to the global ML model. The live demonstration will be carried out on a Kubernetes cluster using Fraunhofer HHI’s Distributed Learning Framework (DLFi) software solution.