Silicon-plasmonic internal-photoemission detector for 40  Gbit/s data reception

Abstract

Silicon-plasmonics enables the fabrication of active photonic circuits in CMOS technology with unprecedented operation speed and integration density. Regarding applications in chip-level optical interconnects, fast and efficient plasmonic photodetectors with ultrasmall footprints are of special interest. A particularly promising approach to silicon-plasmonic photodetection is based on internal photoemission (IPE), which exploits intrinsic absorption in plasmonic waveguides at the metal-dielectric interface. However, while IPE plasmonic photodetectors have already been demonstrated, their performance is still far below that of conventional high-speed photodiodes. In this paper, we demonstrate a novel class of IPE devices with performance parameters comparable to those of state-of-the-art photodiodes while maintaining footprints below 1 μm 2 . The structures are based on asymmetric metal-semiconductormetal waveguides with a width of less than 75 nm. We measure record-high sensitivities of up to 0.12 A/W at a wavelength of 1550 nm. The detectors exhibit opto-electronic bandwidths of at least 40 GHz. We demonstrate reception of on-off keying data at rates of 40 Gbit/s.

High-bandwidth and high-responsivity waveguide-integrated plasmonic germanium photodetector

“…In the last few years, the surge of research in waveguide-integrated plasmonic photodetectors has produced results that show very promising performance improvements. In plasmonic photodetectors relying on a hot carrier photodetection schema, a bandwidth of 40 GHz and a responsivity of 0.12 A/W at 1550 nm was measured at a bias voltage of 3.5 V in a metalinsulator-metal (MIM) waveguide arrangement with a footprint below 1 μm 2 [9]. Another arrangement relies on the inverse-DLSPP waveguide design where a responsivity of 0.085 A/W at 1550 nm wavelength was measured [10,11].…”

Harvesting the loss: surface plasmon-based hot electron photodetection

“…With this detection scheme, a bandwidth up to 1 GHz has been achieved while also maintaining a responsivity of 3.5 mA/W at a negative bias of −21 V [122]. Recently, the bandwidth is further improved and a hot electron photodetector with data reception rate of 40 Gbit/s has been demonstrated [128]. A Schottky detector has also been applied to Si-cored fiber [129] for applications such as power monitoring in optical fiber communication.…”

Enhanced Photoelectric and Photothermal Responses on Silicon Platform by Plasmonic Absorber and Omni‐Schottky Junction

“…Realization of sub‐band gap photodetection, spectral modulation and imaging on a silicon platform by plasmonic hot electrons is technically important for future chip‐scale optoelectronic devices. Very recently, various plasmonic hot electron mediated on‐chip and free‐space photodetectors were proposed and demonstrated experimentally in the literature . For instance, using the self‐aligned approach of local oxidation of silicon (LOCOS) on a silicon‐on‐insulator substrate, a waveguide‐based hot electron photodetector operating at telecom wavelengths has been demonstrated exhibiting a responsivity of 12.5 mA/W .…”

“…[29][30][31][32][33][34][35][36] For instance, using the self-aligned approach of local oxidation of silicon (LOCOS) on a silicon-oninsulator substrate, a waveguide-based hot electron photodetector operating at telecom wavelengths has been demonstrated exhibiting a responsivity of 12.5 mA/W. [30] Notably, by forming asymmetric MSM junctions on the side facets of the silicon waveguide, researchers have succeeded in obtaining a data reception rate of 40 Gbit/s, [32] because of the ultrafast dynamics of the hot electron generation and injection. These silicon waveguidebased plasmonic photodetectors with strong mode confinement allow the guiding waves to propagate and be naturally absorbed adjacent to the Schottky interface and therefore enable efficient hot electron ejection.…”