With the demand for faster data processing speeds, expectations for optoelectronic integrated circuits (OEIC) or phonics-electronics convergence circuits are increasing. For that purpose, photonics integrated circuits based on a silicon platform are suitable due to their high compatibility with electronic circuits. In this paper, light sources, especially semiconductor lasers and their integration technologies on a Si platform will be reviewed. First, several kinds of light source integration technologies and their status are explained. Then, heterogeneous integration technologies, which the author is mainly working on, are reviewed. Finally, laser characteristics using the heterogeneous integration technology and future prospects will be described.

This review is concerned with a highly controllable holographic optical tweezers (HOTs) system that was developed to manipulate micro objects in the microscopic region. The process can be interactively carried out by virtue of time-division multiplexing of computer-generated holograms and the shifting theorem in the Fourier transform to displace the carrier spot in the focal plane of an objective lens. Time-division multiplexing was used to quasi-simultaneously generate two different intensity patterns, a carrier beam spot and a beam-spots array, by alternately feeding the corresponding hologram patterns to a spatial light modulator. The study on the trapping stability is demonstrated by a numerical simulation using the Smoluchowski equation and the generalized Lorentz-Mie theory model. The applicability of the on-demand HOTs system will be shown throughout the review.

In the medical field, several modalities such as CT, MRI, ultrasound, PET, endoscopy, and microscopy are commercially available and clinically in use. However, in many cases those modalities are used independently. In some modalities there are very high resolution machines for a special or research purpose but the similarity or non-similarity of signals between different resolution machines have not been clarified yet. The authors are studying technologies related to multiple modalities and multi-scale devices under a project entitled “Multimodal Medical Engineering.” In this article, we introduce our current research activities on three main topics: ultrasound, MRI and optics (pathology).

This article describes a novel spectral resolution enhancement technique for widespread multi-channel spectrometers, while maintaining their attractive advantages such as high-speed measurement, compactness, low-cost, and robustness. It aims to inexpensively provide a high performance spectrometer that can be used under various environments of diversifying needs in future applications like IoT. The well-known Vernier based technique enables the providing of superior spectral resolution performance in a multi-channel spectrometer through a simple change of the system arrangement and represents a critical step towards low-cost real-time spectral monitoring of dynamic events in various situations in our daily lives.

Self-propagating exothermic multilayer films are very attractive as a heat source because they can produce the heat by applying a small external energy. The heat performance is dependent on the combination of two metals, the atomic ratio, the bilayer thickness and the overall thickness, which indicates that the performance is tunable to match the application. The authors are using a sputtered Al/Ni multilayer film for reactive solder bonding. The film can melt solder within a second, so two Si wafers can be solder-bonded quickly without a furnace. Furthermore, no emissions are generated during the exothermic reaction. The environment-friendly reactive soldering technique has potential as one of the future key semiconductor packaging technologies.

We demonstrated the spontaneous formation of Ir metal nanopillars embedded in Ir:SrTiO₃ thin films in order to enhance the efficiency of photoelectrochemical water splitting. The interface between the metallic Ir nanopillar and the Ir:SrTiO₃ thin film forms a tubular Schottky junction around each pillar. The photocarrier transport efficiency is strongly enhanced in the depleted interface regions, achieving over 80% utilization of photogenerated carriers under visible light in the 400 to 600 nm wavelength range. The three-dimensional interface concept using spontaneously formed nanopillars would provide us a variety of novel functionalities in oxide and semiconductor devices.

Confocal laser scanning microscopes (CLSM) have been used for high-definition luminescence observations in a wide range of fields such as physics and biology. In this article, the basic system and principle of CLSM, and the role and selection of devices are explained for beginners who want to assemble a CLSM by installing optical devices on an optical surface plate. There are different decisions to make to assemble a CLSM, such as which optical device to use and the adjustment method for the optical system, however, this article explains the minimum required devices for the construction of CLSM.