Angular-dependent photodetection enhancement by a metallic circular disk optical antenna

Abstract

In this paper, we analyze the plasmonic resonance excited by linearly polarized longwave infrared (LWIR) plane waves in a metallic circular disk optical antenna (MCDA). The surface current distributions are simulated at different wavelengths, incident angles, and polarizations. The excited surface plasmonic resonance waves (SPRs) are different from the Bessel-type of SPR modes and closely resemble those in a monopole antenna. An MCDA coupled LWIR quantum dot infrared photodetector (QDIP) was fabricated and measured at different LWIR plane wave wavelengths and incident angles. A linear correlation between the enhancement ratio and the integrated square of the current is obtained, indicating the monopole antenna effect is a dominating factor for the plasmonic enhancement.

Angle-Selective Photodetection in Ge/Si Quantum Dot Photodiodes Enhanced by Microstructured Hole Arrays

“…The light-trapping holes enhance the absorption of Ge quantum dots and extend the operational wavelength of the photodiode to 2 µm with the responsivity of about 10 mA/W. This represents (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40) fold increased efficiency compared to conventional flat QDIP without holes. The enhancement spectrum consists of both the broad band and the resonance peaks.…”

“…However, it could be very useful in many applications, such as high response angle-sensing photodetection, solar energy conversion, laser beacon tracking, lensless imaging, etc. [32][33][34][35][36][37]. In the present work, we study the angular-dependent photodetection in Ge/Si QDIPs contaning microhole arrays on their surface.…”

Analysis of mutual couplings in a concentric circular ring plasmonic optical antenna array

“…Depending on the optical antenna structures, localized surface plasmonic resonance (LSPR) modes 12, 13 can be excited in optical antennas 1–5, 14–16 , which are referred to as plasmonic optical antennas (POAs). POA enhanced quantum dot infrared photodetectors (QDIPs) have been reported with enhanced photocurrents and directional antenna gains 6, 17, 18 . The analysis of the near-field of POAs and their roles in the plasmonic enhancement have also been reported 6 .…”

A back side configured pointed dipole plasmonic optical antenna array enhanced quantum dot infrared photodetector

“…Optical antenna enhanced quantum dot infrared photodetectors (QDIPs) have been reported with enhanced photocurrent and directional antenna gains [3,11,12]. However, in most of the reported optical antenna enhanced QDIPs, the antennas are the top side configured [3,[11][12][13], where the incident light is illuminated from the antennas side (i.e. top side), goes through antennas, and then reaches the QDIPs.…”

“…The |E| increases as the gap decreases. Compared to other plasmonic structures such as 2DSHA [8,13,25], circular disks [3,12], and circular rings [26], the pointed dipole antennas offer significantly higher E-fields in the gap when the gap is small. Such high E-fields can provide high enhancement for ultra-small detectors that can fit in the gap region with proper sidewall passivation.…”