Open AccessOn‐chip integration of laser‐ablated zone plates for detection enhancement of InGaAs bow‐tie terahertz detectors
Author(s) -
Minkevičius L.,
Tamošiūnas V.,
Madeikis K.,
Voisiat B.,
Kašalynas I.,
Valušis G.
Publication year - 2014
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2014.1893
Subject(s) - terahertz radiation , detector , wafer , optics , optoelectronics , laser , materials science , chip , gallium arsenide , signal (programming language) , substrate (aquarium) , bow tie , physics , antenna (radio) , engineering , electrical engineering , telecommunications , oceanography , geology , computer science , programming language
One order of magnitude detection enhancement of bow‐tie‐shaped InGaAs‐based terahertz detectors by on‐chip incorporation of the secondary diffractive optics is reported. Zone plates were produced directly on the bottom surface of 500 µm‐thick InP substrate using the direct laser write technique after an array of InGaAs detectors was formed on the front surface of the wafer. Measurements of detected signal dependence on the angle of the incident wave were performed at 0.76 THz and compared with finite‐difference time‐domain simulation results. Good correlation of the results shows that the observed enhancement is indeed caused by the focusing performance of the zone plate rather than by the exceptional sensitivity of the single detector.