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A 2 × 2 3-dB coupler is one of the essential photonic components, as a building block of Mach-Zehnder interferometers, to realize large-scale photonic integrated circuits. Unlike typical 2 × 2 3-dB couplers based on direction couplers or multimode interference couplers, adiabatic couplers offer various advantages such as broadband operation and superior fabrication tolerance thanks to their unique operating mechanism of adiabatic mode evolution. However, an adiabatic coupler typically requires a long device length for ideal adiabatic operation without the excitations of unwanted modes. Here, we report on a compact 2 × 2 3-dB adiabatic coupler designed using the shortest mode transformer method. By optimizing the profile of the waveguide widths and the gap spacing, the compact 3-dB coupler was designed with a short coupling length of 23.2 μm. The fabricated device exhibits a 3-dB splitting ratio with less than ± 0.3 dB power oscillation and a low excess loss of 0.23 dB over a broad wavelength range of 1485–1620 nm. To the best of our knowledge, our coupler has the shortest length among the adiabatic couplers with a minimum feature size of 200 nm, reported to date.

Four-dimensional (4D) films, which provide special physical effects to the audience with audiovisual stimuli, are gaining more popularity and acceptance. One of the most frequent 4D effects is the object-based motion effect, which refers to the vestibular stimulus generated by a motion chair to emphasize a moving object of interest, e.g., the flying iron man, displayed on the screen. In this paper, we present an algorithm for synthesizing convincing object-based motion effects automatically from a given object motion trajectory. While previous approaches use the 2D object position on the screen as input, our method takes the 3D position and orientation of the object in the camera space and computes its motion proxy that reflects both the object translation and rotation, as well as its size to the viewers' eyes. The proxy is determined based on the results of a perceptual experiment that presents an optimal additive rule of the translation and rotation information scaled by the object's visual size. The motion proxy is fed to a motion cueing algorithm (MCA) that computes the command using a washout filter or model predictive control. The most appropriate MCA for our purpose is selected from six candidates by a user study. We also consider the effects of visual perception by incorporating two types of motion field equations into the computation of the visually perceived velocity. The results of a user study indicate that our algorithm can generate compelling object-based motion effects that better enhance the 4D film viewing experience than the previous methods.

We have experimentally demonstrated on-chip chalcogenide resonators with Q-factor of 1.1x107 using a new fabrication method which avoids direct etching of chalcogenide film. Low threshold power (12mW) Brillouin laser is implemented using the fabrication method. Also, cascaded lasing up to 3rd stokes have been observed with 42 mW of pump power.

We report on the flip chip packaging of Micro-Electro-Mechanical System (MEMS)-based digital silicon photonic switching device and the characterization results of 12 × 12 switching ports. The challenges in packaging N 2 electrical and 2N optical interconnections are addressed with single-layer electrical redistribution lines of 25 μm line width and space on aluminum nitride interposer and 13° polished 64-channel lidless fiber array (FA) with a pitch of 127 μm. 50 μm diameter solder spheres are laser-jetted onto the electrical bond pads surrounded by suspended MEMS actuators on the device before fluxless flip-chip bonding. A lidless FA is finally coupled near-vertically onto the device gratings using a 6-degree-of-freedom (6-DOF) alignment system. Fiber-to-grating coupler loss of 4.25 dB/facet, 10-11 bit error rate (BER) through the longest optical path, and 0.4 μs switch reconfiguration time have been demonstrated using 10 Gb/s Ethernet data stream.

We present the design of an analog Silicon Photonic MEMS phase shifter based on vertically moving adiabatic couplers. Using a two-step electrostatic actuation method, the phase shifter can be turned on selectively by applying an actuation voltage on a first pair of electrodes, and the phase of the optical signal can be tuned continuously by applying an actuation voltage at a second electrode pair. A mechanical movement of only 20nm at 19V actuation voltage allows for a full π phase shift. The design exhibits a compact footprint of 60um × 44um and low excess insertion loss below 0.1dB.

We review the state of the art of silicon photonic switches with MEMS actuation, which have high scalability, low power consumption, and digital switching characteristic. We also present the potential of polarization insensitive switching by MEMS-actuated silicon photonic switches.

We report on the first electrical and optical packaging of digital silicon photonic MEMS switches with 12×12 ports, 13∼18dB fiber-to-fiber loss, 10−11 BER for 10-Gb/s datastream, 0.4μs switch reconfiguration time, and

Large-scale silicon photonic switches with high port counts (64×64) and low on-chip losses have been realized by integrating micro-electro-mechanical-system (MEMS) actuators with silicon photonics. The switch has fast (sub-microsecond) switching time, and has potential applications in reconfigurable networks for data-intensive computing.

We report on monolithically integrated 64×64 broadband digital silicon photonic MEMS switches with sub-microsecond switching time (0.9 μs), high extinction ratio (65 dB), low on-chip insertion loss (5.1 dB), broadband operation (1460–1580 nm wavelength) and compact footprint (7×7 mm2).

We report on the reliability test of 50×50 digital silicon photonic MEMS switches. The switch operates reliably over 10 billion cycles and up to 48 hours of continuous contact in ambient environment without packaging.

We present a scalable silicon photonic MEMS switch with an actuation scheme requiring only 2N electrical contacts for an N×N switch matrix. Unit cell size is 145µm × 145µm and switching loss 1.5dB at 1550nm.

In this paper, we studied for the transmission of message and voice using CCNx that is one of the Content Centric Network(CCN) projects. CCN is considered as a way to solve the explosive growth of Internet traffic. In order to apply CCN to the common services that are widely used, we developed applications that send message and voice. The application can operate without a separate server by using CCNx. Using mobile devices such as a raspberry pie, we tested in an environment similar to the actual environment. In this result, we can confirm that CCN is applicable to the general services.

We report on fully reconfigurable CROWs with MEMS-tunable waveguides. Resonatorto-resonator and resonator-to-waveguide coupling are fully tunable. Resonance of a resonator is also widely tunable to cover its full FSR. The static power consumption per tunable coupler is below 10nW. (C) 2021 The Author(s)

We demonstrate a die level release process for silicon photonic MEMS structures, that is compatible with dies from a standard silicon photonics foundry process which are only several square millimeters in size.