Periodic Reporting for period 3 - TeraSHAPE (Terahertz Waveform Synthesis and Analysis Using Hybrid Photonic-Electronic Circuits)
Período documentado: 2021-05-01 hasta 2022-10-31
Generation, detection, and processing of electrical and electromagnetic waveforms is one the most important technical foundations of modern society. Digital signal processing (DSP), in particular, has revolutionized many areas of science and engineering, with widespread applications in communications, radar and navigation, industrial metrology and sensing, chemical analysis, or medical diagnostics. Over the last decades, the processing power of digital computing systems increased by orders of magnitude, mainly driven by the tremendous evolution and the outstanding scalability of complementary metal-oxide-semiconductor (CMOS) electronics. This has opened a door towards real-time processing of data streams of hundreds of gigabits per second, exploiting massively parallel computation on tens of billions of transistors at comparatively low internal clock speed. In contrast to this, the analogue bandwidth of electronic circuits is much more difficult to scale due to limited switching speed of semiconductor devices, strongly increased transmission line losses at high frequencies, and the considerable complexity associated with high-speed circuit packaging and assembly.
TeraSHAPE aims at overcoming these limitations by establishing the methodological and technological foundations of novel signal processing concepts in the frequency range between 100 GHz and 1 THz. By combining massively parallel processing in digital electronic circuits with synthesis and analysis of broadband waveforms in the optical domain, analogue signal processing bandwidths of hundreds of gigahertz will come into reach. This approach can capitalize on great progress in the fields of photonic integrated circuits and optical frequency combs, which act as precise references for broadband signal generation and detection. Specifically, we exploit powerful photonic integrated circuits (PIC) for spectrally sliced processing of phase-locked optical carriers that are derived from chip-scale frequency comb sources. To convert waveforms between optical and THz frequencies, TeraSHAPE will explore novel concepts for ultra-fast electro-optic modulators and photodetectors with bandwidths of hundreds of gigahertz. Advances on the device level will be complemented by scalable assembly concepts for high-performance systems, where TeraSHAPE will explore three-dimensional additive fabrication techniques both for hybrid photonic integration and for realizing sub-mm waveguides for THz signals. The viability and the application potential of the TeraSHAPE concepts will be explored and demonstrated in dedicated experiments that target selected applications of high relevance, comprising, e.g. high-speed wireless communications in future sixth-generation (6G) wireless networks or THz signal processing for scientific applications.
TeraSHAPE aims at overcoming these limitations by establishing the methodological and technological foundations of novel signal processing concepts in the frequency range between 100 GHz and 1 THz. By combining massively parallel processing in digital electronic circuits with synthesis and analysis of broadband waveforms in the optical domain, analogue signal processing bandwidths of hundreds of gigahertz will come into reach. This approach can capitalize on great progress in the fields of photonic integrated circuits and optical frequency combs, which act as precise references for broadband signal generation and detection. Specifically, we exploit powerful photonic integrated circuits (PIC) for spectrally sliced processing of phase-locked optical carriers that are derived from chip-scale frequency comb sources. To convert waveforms between optical and THz frequencies, TeraSHAPE will explore novel concepts for ultra-fast electro-optic modulators and photodetectors with bandwidths of hundreds of gigahertz. Advances on the device level will be complemented by scalable assembly concepts for high-performance systems, where TeraSHAPE will explore three-dimensional additive fabrication techniques both for hybrid photonic integration and for realizing sub-mm waveguides for THz signals. The viability and the application potential of the TeraSHAPE concepts will be explored and demonstrated in dedicated experiments that target selected applications of high relevance, comprising, e.g. high-speed wireless communications in future sixth-generation (6G) wireless networks or THz signal processing for scientific applications.
Activities of the first reporting period started from a quantitative analysis of system concepts based on dedicated models for photonic-electronic synthesis and analysis of signals with bandwidths beyond 100 GHz, so-called T-waves. These models have been experimentally tested and build the base of a first generation of photonic electronic THz arbitrary waveform analyzers and generators (TAWA and TAWG). We have further realized and demonstrated the underlying devices and technologies for the envisaged systems such as high-speed signal optical-to-THz (O/T) and THz-to-optical (T/O) signal converters as well as hybrid photonic multi-chip modules that rely on 3D-nanoprinted coupling elements. Implementation and experimental exploration of a first generation of TAWA and TAWG demonstrators is ongoing and will be continuously improved. With respect to application demonstrations, we have focused on photonic-electronic signal analysis and synthesis for high-speed wireless communications in future sixth-generation (6G) wireless networks. In parallel, we have designed a series of photonic integrated circuits (PIC) for the second generation of TAWA and TAWG – the fabrication in external foundries is currently ongoing. The findings of the first project phase have triggered a series of further activities in the group of the principal investigator (PI), and the results have been published in a series of articles in high-impact journals in the field of Optica & Photonics as well as in contributions to internationally leading conferences. Main results comprise, e.g. hybrid silicon photonic and silicon plasmonic electro-optic modulators with unprecedented efficiency [23] or speed [16] that lend themselves to T/O conversion, silicon-plasmonic photodetectors for O/T conversion [20], advanced photonic multi-chip modules based on 3D-printed chip-chip connections [10], [24], as well as demonstrations of novel signal processing concepts for future sixth-generation (6G) wireless networks [3], [20].
In the first reporting period, we have demonstrated important progress beyond the state of the art related to components [16], [20], [23], [24], systems [10], as well as applications [3], [20]. These activities shall be continued in the second reporting period. Besides activities on the device level, we plan to conclude the demonstration and testing of our first-generation TAWA and TAWG and to further advance our application demonstrations. In this context, we shall not only target applications in communications, but also work on THz signal processing for scientific applications in the field of THz metrology. In parallel, we will further reinforce our activities in the field of 3D-printed functional devices, aiming at a demonstration of functional THz structures. With respect to further system demonstrations, we will implement and test the second generation of TAWA and TAWG demonstrators, which will rely on photonic integrated circuits (PIC) that are currently being fabricated. This aspect will be key with respect to future deployment of such systems in technical applications where robustness, footprint, cost and power consumption are of high relevance. Based on the results of these demonstrations, we will explore further possibilities to transfer TeraSHAPE results to industrial applications.