Digital detection of Alzheimer's disease using smiles and conversations with a chatbot.

In super-aged societies, dementia has become a critical issue, underscoring the urgent need for tools to assess cognitive status effectively in various sectors, including financial and business settings. Facial and speech features have been tried as cost-effective biomarkers of dementia including Alzheimer's disease (AD). We aimed to establish an easy, automatic, and extensive screening tool for AD using a chatbot and artificial intelligence.

Si-nanowire-based multistage delayed Mach-Zehnder interferometer optical MUX/DeMUX fabricated by an ArF-immersion lithography process on a 300 mm SOI wafer.

We report good phase controllability and high production yield in Si-nanowire-based multistage delayed Mach-Zehnder interferometer-type optical multiplexers/demultiplexers (MUX/DeMUX) fabricated by an ArF-immersion lithography process on a 300 mm silicon-on-insulator (SOI) wafer. Three kinds of devices fabricated in this work exhibit clear 1×4 Ch wavelength filtering operations for various optical frequency spacing. These results are promising for their applications in high-density wavelength division multiplexing-based optical interconnects.

Low-loss, flat-topped and spectrally uniform silicon-nanowire-based 5th-order CROW fabricated by ArF-immersion lithography process on a 300-mm SOI wafer.

We report superior spectral characteristics of silicon-nanowire-based 5th-order coupled resonator optical waveguides (CROW) fabricated by 193-nm ArF-immersion lithography process on a 300-mm silicon-on-insulator wafer. We theoretically analyze spectral characteristics, considering random phase errors caused by micro fabrication process. It will be experimentally demonstrated that the fabricated devices exhibit a low excess loss of 0.

High-output-power, single-wavelength silicon hybrid laser using precise flip-chip bonding technology.

An Si/III-V hybrid laser oscillating at a single wavelength was developed for use in a large-scale Si optical I/O chip. The laser had an InP-based reflective semiconductor optical amplifier (SOA) chip integrated with an Si wavelength-selection-mirror chip in a flip-chip configuration. A low coupling loss of 1.

Compact and low power operation optical switch using silicon-germanium/silicon hetero-structure waveguide.

We proposed a silicon-based optical switch with a carrier-plasma-induced phase shifter which employs a silicon-germanium (SiGe) / silicon (Si) hetero-structure in the waveguide core. A type-I hetero-interface formed by SiGe and Si is expected to confine carriers effectively in the SiGe waveguide core. The fabricated Mach-Zehnder optical switch shows a low switching power of only 1.

Optical 60° hybrid for demodulating six-level DPSK signal.

We propose and demonstrate an optical 60° hybrid for demodulating optical signals with six-level DPSK modulation format. The proposed device consisting of a paired-interference 2∶6MMI coupler, phase shifters, and 2∶2MMI couplers with an asymmetric splitting ratio of 72∶28 exhibited hexagonal phase response over a C-band range.

Optical 45 degrees hybrid for demodulating 8-ary DPSK signal.

We propose a novel optical 45 degrees hybrid employing a 2 x 8 paired interference based multimode interference (MMI) coupler, three phase shifters and three 2 x 2 optical couplers. Since the proposed 45 degrees hybrid can demodulate an 8-ary differential phase shift keyed (8-DPSK) signal with only one delayed Mach-Zehnder interferometer (DMZI), the demodulator has simpler configuration and much smaller device dimensions than conventional 8-DPSK demodulators consisting of four pairs of DMZIs and 2 x 2 optical couplers. We calculate and experimentally demonstrate octagonal phase response of the proposed 45 degrees hybrid with a relative phase deviation of < +/- 5 degrees over 32-nm-wide spectral range.

Compact optical 90 degrees hybrid employing a tapered 2x4 MMI coupler serially connected by a 2x2 MMI coupler.

We propose a novel optical 90 degrees hybrid employing a paired-interference-based tapered 2x4 multimode interference coupler and a 2x2 multimode interference coupler. It was experimentally shown that the proposed 90 degrees hybrid has very short device length of less than 227 mum and is never accompanied by any waveguide intersections for coupling to balanced photodiodes. The proposed device exhibited quadrature phase response with a common-mode rejection ratio of more than 20dB and a phase deviation of less than 5 degrees over C-band spectral range.

Optical 90 degree hybrid with broad operating bandwidth of 94 nm.

We propose an optical 90 degree hybrid where no waveguide intersection in coupling to balanced photodiodes is required for coherent detection. The proposed device consisting of a paired-interference 2x4 multimode interference (MMI) coupler, a phase shifter, and a 2x2 MMI coupler exhibited quadrature phase response over a 94-nm-wide spectral range.