The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Andrew Y. Shin - One of the best experts on this subject based on the ideXlab platform.
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Vertical-junction Photodiodes for smaller pixels in retinal prostheses.
Journal of neural engineering, 2021Co-Authors: Tiffany W. Huang, Theodore I. Kamins, Zhijie Charles Chen, Bing-yi Wang, Mohajeet Bhuckory, Ludwig Galambos, Tong Ling, Sean Afshar, Andrew Y. ShinAbstract:Objective. To restore central vision in patients with atrophic age-related macular degeneration, we replace the lost photoreceptors with photovoltaic pixels, which convert light into current and stimulate the secondary retinal neurons. Clinical trials demonstrated prosthetic acuity closely matching the sampling limit of the 100 μm pixels, and hence smaller pixels are required for improving visual acuity. However, with smaller flat bipolar pixels, the electric field penetration depth and the Photodiode Responsivity significantly decrease, making the device inefficient. Smaller pixels may be enabled by (1) increasing the diode Responsivity using vertical p-n junctions and (2) directing the electric field in tissue vertically. Here, we demonstrate such novel Photodiodes and test the retinal stimulation in a vertical electric field. Approach. Arrays of silicon Photodiodes of 55, 40, 30, and 20 μm in width, with vertical p-n junctions, were fabricated. The electric field in the retina was directed vertically using a common return electrode at the edge of the devices. Optical and electronic performance of the diodes was characterized in-vitro, and retinal stimulation threshold measured by recording the visually evoked potentials (VEPs) in rats with retinal degeneration. Main results. The Photodiodes exhibited sufficiently low dark current (
Rongrui Liu - One of the best experts on this subject based on the ideXlab platform.
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4 25 ghz uni traveling carrier Photodiode arrays monolithic with inp based awg demultiplexers using the selective area growth technique
Chinese Optics Letters, 2017Co-Authors: Qin Han, Pan Pan, Xiaohong Yang, Yubing Wang, Rongrui LiuAbstract:We use the selective area growth (SAG) technique to monolithically integrate InP-based 4-channel arrayed waveguide gratings (AWGs) with uni-traveling carrier Photodiode arrays at the O-band. Two kinds of channel spacing demultiplexers of 20 nm and 800 GHz are adopted for potential 100 Gbps coarse wavelength division multiplexing and local area network wavelength division multiplexing systems, with an evanescent coupling plan to facilitate the SAG technique into device fabrication. The monolithic chips in both channel spacings exhibit uniform bandwidths over 25 GHz and a Photodiode Responsivity of 0.81 A/W for each channel, in agreement with the simulated quantum efficiency of 80%. Cross talk levels are below −20 dB for both channel spacing chips.
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4 × 25 GHz uni-traveling carrier Photodiode arrays monolithic with InP-based AWG demultiplexers using the selective area growth technique
Chinese Optics Letters, 2017Co-Authors: Qin Han, Pan Pan, Xiaohong Yang, Wang Yubing, Rongrui LiuAbstract:We use the selective area growth (SAG) technique to monolithically integrate InP-based 4-channel arrayed waveguide gratings (AWGs) with uni-traveling carrier Photodiode arrays at the O-band. Two kinds of channel spacing demultiplexers of 20 nm and 800 GHz are adopted for potential 100 Gbps coarse wavelength division multiplexing and local area network wavelength division multiplexing systems, with an evanescent coupling plan to facilitate the SAG technique into device fabrication. The monolithic chips in both channel spacings exhibit uniform bandwidths over 25 GHz and a Photodiode Responsivity of 0.81 A/W for each channel, in agreement with the simulated quantum efficiency of 80%. Cross talk levels are below −20 dB for both channel spacing chips.
Tiffany W. Huang - One of the best experts on this subject based on the ideXlab platform.
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Vertical-junction Photodiodes for smaller pixels in retinal prostheses.
Journal of neural engineering, 2021Co-Authors: Tiffany W. Huang, Theodore I. Kamins, Zhijie Charles Chen, Bing-yi Wang, Mohajeet Bhuckory, Ludwig Galambos, Tong Ling, Sean Afshar, Andrew Y. ShinAbstract:Objective. To restore central vision in patients with atrophic age-related macular degeneration, we replace the lost photoreceptors with photovoltaic pixels, which convert light into current and stimulate the secondary retinal neurons. Clinical trials demonstrated prosthetic acuity closely matching the sampling limit of the 100 μm pixels, and hence smaller pixels are required for improving visual acuity. However, with smaller flat bipolar pixels, the electric field penetration depth and the Photodiode Responsivity significantly decrease, making the device inefficient. Smaller pixels may be enabled by (1) increasing the diode Responsivity using vertical p-n junctions and (2) directing the electric field in tissue vertically. Here, we demonstrate such novel Photodiodes and test the retinal stimulation in a vertical electric field. Approach. Arrays of silicon Photodiodes of 55, 40, 30, and 20 μm in width, with vertical p-n junctions, were fabricated. The electric field in the retina was directed vertically using a common return electrode at the edge of the devices. Optical and electronic performance of the diodes was characterized in-vitro, and retinal stimulation threshold measured by recording the visually evoked potentials (VEPs) in rats with retinal degeneration. Main results. The Photodiodes exhibited sufficiently low dark current (
Gunther Roelkens - One of the best experts on this subject based on the ideXlab platform.
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Transfer Print Integration of Waveguide-Coupled Germanium Photodiodes Onto Passive Silicon Photonic ICs
Journal of Lightwave Technology, 2018Co-Authors: Grigorij Muliuk, Jing Zhang, Amin Abbasi, Antonio Jose Trindade, Christopher A. Bower, Dries Van Thourhout, Gunther RoelkensAbstract:We demonstrate the integration of waveguide-coupled germanium Photodiodes onto passive silicon waveguide circuits by means of transfer printing. This involves the release of the Photodiodes from the silicon-on-insulator source wafer by underetching the buried oxide layer while protecting the back-end stack. Tethers were formed to keep the released Photodiode coupons in place. Coupons were then transfer printed to a silicon photonic target wafer with an alignment accuracy better than ±1 μ m. 0.66 A/W waveguide-referred Photodiode Responsivity at 1550 nm was obtained. High-speed measurements yielded open eye diagrams at 40 Gb/s.
Qin Han - One of the best experts on this subject based on the ideXlab platform.
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4 25 ghz uni traveling carrier Photodiode arrays monolithic with inp based awg demultiplexers using the selective area growth technique
Chinese Optics Letters, 2017Co-Authors: Qin Han, Pan Pan, Xiaohong Yang, Yubing Wang, Rongrui LiuAbstract:We use the selective area growth (SAG) technique to monolithically integrate InP-based 4-channel arrayed waveguide gratings (AWGs) with uni-traveling carrier Photodiode arrays at the O-band. Two kinds of channel spacing demultiplexers of 20 nm and 800 GHz are adopted for potential 100 Gbps coarse wavelength division multiplexing and local area network wavelength division multiplexing systems, with an evanescent coupling plan to facilitate the SAG technique into device fabrication. The monolithic chips in both channel spacings exhibit uniform bandwidths over 25 GHz and a Photodiode Responsivity of 0.81 A/W for each channel, in agreement with the simulated quantum efficiency of 80%. Cross talk levels are below −20 dB for both channel spacing chips.
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4 × 25 GHz uni-traveling carrier Photodiode arrays monolithic with InP-based AWG demultiplexers using the selective area growth technique
Chinese Optics Letters, 2017Co-Authors: Qin Han, Pan Pan, Xiaohong Yang, Wang Yubing, Rongrui LiuAbstract:We use the selective area growth (SAG) technique to monolithically integrate InP-based 4-channel arrayed waveguide gratings (AWGs) with uni-traveling carrier Photodiode arrays at the O-band. Two kinds of channel spacing demultiplexers of 20 nm and 800 GHz are adopted for potential 100 Gbps coarse wavelength division multiplexing and local area network wavelength division multiplexing systems, with an evanescent coupling plan to facilitate the SAG technique into device fabrication. The monolithic chips in both channel spacings exhibit uniform bandwidths over 25 GHz and a Photodiode Responsivity of 0.81 A/W for each channel, in agreement with the simulated quantum efficiency of 80%. Cross talk levels are below −20 dB for both channel spacing chips.