PICs for THz

Photonic integrated circuits (PICs) are beneficial as beating sources in CW-THz systems because they allow precise and stable generation of THz signals through the photo mixing of two coherent optical frequencies on a single chip. This integration leads to compact, robust, and low-power THz sources with high-frequency stability and tunability. Additionally, PICs enable cost-effective mass production and easy integration with other photonic components, enhancing the overall performance and scalability of THz systems. They also provide versatility and functionality by incorporating multiple photonic elements, allowing for reconfigurable and multifunctional THz sources on a single platform.

The versatility of custom-designed PICs was fully utilized in a first iteration. The PIC was designed at PTT and manufactured in Fraunhofer HHIs Multi-Project-Wafer Foundry from a InP wafer (1550 nm based). The designed PIC features different configurations for generation of beating signals including two DFB lasers, one sampled-grating DBR laser as well as optical amplifiers and phase shifters on a chip size of 2 mm by 8 mm (shown in the figure). After packaging of the PIC at PTT, the performance of the components is evaluated in photonic CW-THz systems showing very promising results.

In a second iteration, the aim is integration of more THz components (like antennas) towards a fully integrated THz systems together with our project partners in the collaborative research center MARIE as well as Fraunhofer HHI.