Photonic integration requires a versatile packaging technology that enables low-loss interconnects between photonic chips in three-dimensional configurations. In this paper we introduce the concept of photonic wire bonding, where polymer waveguides with three-dimensional freeform geometries are used to bridge the gap between nanophotonic circuits located on different chips. In a proof-of-principle experiment, we demonstrate the fabrication of single-mode photonic wire bonds (PWB) by direct-write two-photon lithography. First-generation prototypes allow for efficient broadband coupling with average insertion losses of only 1.6 dB in the C-band and can carry wavelength-division multiplexing signals with multi-Tbit/s data rates. Photonic wire bonding is well suited for automated mass production, and we expect the technology to enable optical multi-chip systems with enhanced performance and flexibility.

Client-side optics are facing an ever-increasing upgrading pace, driven by upcoming 5G related services and datacenter applications. The demand for a single lane data rate is soon approaching 200 Gbps. To meet such high-speed requirement, all segments of traditional intensity modulation direct detection (IM/DD) technologies are being challenged. The characteristics of electrical and optoelectronic components, and the performance of modulation, coding and digital signal processing (DSP) techniques are being stretched to their limits. In this context, we witnessed technological breakthroughs in several aspects, including development of broadband devices, novel modulation formats and coding, and high-performance DSP algorithms for the past few years. A great momentum has been accumulated to overcome the aforementioned challenges. In this paper, we focus on IM/DD transmissions, and provide an overview of recent research and development efforts on key enabling technologies for 200 Gbps per lane and beyond. Our recent demonstrations of 200 Gbps short-reach transmissions with 4level pulse amplitude modulation (PAM) and discrete multitone signals are also presented as examples to show the system requirements in terms of device characteristics and DSP performance. Apart from digital coherent technologies and advanced direct detection systems, such as Stokes-vector and Kramers-Kronig schemes, we expect high-speed IM/DD systems will remain advantageous in terms of system cost, power consumption and footprint for short reach applications in the short-to mid-term perspective.

No abstract

Abstract:We have demonstrated a traveling-wave electroabsorption modulator based on the hybrid silicon platform. For a device with a 100 μm active segment, the small-signal electro/optical response renders a 3 dB bandwidth of around 42 GHz and its modulation efficiency reaches 23 GHz/V. A dynamic extinction ratio of 9.8 dB with a driving voltage swing of only 2 V was demonstrated at a transmission rate of 50 Gb/s. This represents a significant improvement for modulators compatible with integration of silicon-based photonic integrated circuits. ©2011 Optical Society of America