Surface plasmon waveguide Schottky detector

Abstract

A surface plasmon polariton detector is demonstrated at infra-red wavelengths. The device consists of a metal stripe on silicon forming a Schottky contact thereon and supporting surface a plasmon polariton mode that is strongly confined and localised to the metal-semiconductor interface. Detection of optical radiation below the bandgap of silicon (at infrared wavelengths) occurs through internal photoemission. Responsivities of 0.38 and 1.04 mA/W were measured via end-fire coupling to a tapered optical fibre, at room temperature and at a wavelength of 1280 nm, for gold and aluminium stripes on n-type silicon, respectively. The device can be integrated with other structures used in nano-plasmonics, nano-photonics or silicon-based photonics, and it holds promise for short-reach optical interconnects and power monitoring applications.

Narrowband photodetection in the near-infrared with a plasmon-induced hot electron device

“…Device measurements showed a drastic increase in the responsivity and internal quantum efficiency (IQE) relative to earlier nanoantenna-based photodetectors, while simultaneously narrowing the spectral width of the photodetector response and preserving free-space coupling and polarization selectivity. The responsivity of this device (0.6 mA W À 1 at zero bias voltage) is similar to responsivities reported in the literature for propagating plasmon sensors 24 . The IQE of this photodetector is B0.2%, 20 times larger than the previously reported literature value of 0.01% for nanoantenna-based devices 16 .…”

Harvesting the loss: surface plasmon-based hot electron photodetection

“…Hot electrons have also played a role in realizing on-chip photodetectors based on silicon with several demonstrations [45,85,87,[118][119][120][121][122][123] over the past several years. Despite the success of using silicon photonics for controlling light emission, propagation, and modulation, the use of silicon as an active absorbing material in the telecommunication band is challenging due its transparency in this regime.…”

“…Researchers have proposed [118,119] and experimentally demonstrated [120] waveguide-based Schottky detectors by putting metal stripes on silicon, forming SPP waveguides ( Figure 4A). Internal responsivity of 0.38 and 1.04 mA/W were measured at a wavelength of 1280 nm [120] for gold and aluminum stripes on n-type silicon, respectively.…”

“…Internal responsivity of 0.38 and 1.04 mA/W were measured at a wavelength of 1280 nm [120] for gold and aluminum stripes on n-type silicon, respectively. A silicon waveguide-based SPP Schottky photodetector operating at telecom wavelengths has also been developed [45] (Figure 4B).…”

“…MIM diodes can be built on a wider range of devices such as polymer waveguides and optical fiber. In addition, multiple metal contacts [87,[120][121][122] are not required here, simplifying the geometry [47,104], although quantum efficiency suffers when compared to a Schottky diode. …”