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Nano-Patterned High-Responsivity Gaas Metal-Semiconductor-Metal Photodetector, Ayman Karar, Chee Leong Tan, Kamal Alameh, Yong Tak Lee
Nano-Patterned High-Responsivity Gaas Metal-Semiconductor-Metal Photodetector, Ayman Karar, Chee Leong Tan, Kamal Alameh, Yong Tak Lee
Research outputs 2011
In this paper, we use the finite difference time-domain (FDTD) method to optimize the light absorption of an ultrafast nano-grating plasmonic GaAs metal-semiconductor-metal photodetector (MSM-PD) employing double metal nano-gratings. The geometry of the MSM-PD is theoretically investigated, leading to improved light absorption near the design wavelength of GaAs due to plasmon-assisted electric and magnetic field concentration through a subwavelength aperture. Simulation results show up to 8- and 21-times light absorption enhancement for the single and double nano-grating structure, respectively, in comparison to conventional MSM-PDs. Experimentally, more than 4 times enhancement in photocurrent is demonstrated for a single top nano-grating MSM-PD …
Design Of Laser Multi-Beam Generator For Plant Discrimination, Sreten Askraba, Arie Paap, Kamal Alameh, John Rowe
Design Of Laser Multi-Beam Generator For Plant Discrimination, Sreten Askraba, Arie Paap, Kamal Alameh, John Rowe
Research outputs 2011
Optimisation of the optical signal from the laser multi-spot beam generator employed in a photonic based real-time plant discrimination sensor for use in selective herbicide spraying systems is presented. The plant detection sensor uses a three-wavelength laser diode module that sequentially emits identically-polarized laser light beams through a common aperture, along one optical path. Each laser beam enters a multi-spot beam generator which produces 15 parallel laser beams over a 240mm span. The intensity of the reflected light from each spot is detected by a high-speed line scan image sensor. Plant discrimination is based on calculating the slope of the …