We developed an optical high-speed gaze controller, called the “Saccade Mirror”, and used it to realize a high-speed pan/tilt camera with a high-speed image processor. Generally, in a pan/tilt camera, the gaze is controlled mechanically by rotational actuators. However, because pan/tilt cameras will be expected to use high-speed image processing (≥ 1000 fps), sufficiently high-speed performance of the gaze controller, comparable to the high frame rate, cannot be obtained with the usual method. In our system, the camera itself was fixed, and an external Saccade Mirror subsystem was used for optical gaze control. An arbitrary gaze direction within ±30 deg could be achieved in less than 3.5 ms.

This paper proposes a variable-focus lens with 1-kHz bandwidth. The lens transforms its shape rapidly using the liquid pressure generated by a piezo stack actuator. This mechanism also includes a built-in motion amplifier with high bandwidth to compensate for the short working range of the piezo stack actuator. Prototypes have been developed to validate the proposed design. A 1-kHz bandwidth of the lenses was confirmed by measuring the frequency responses. Refractive power ranging from -1/167 to 1/129 mm^-1 and a maximum resolution of 12.3 cycles/mm were attained.

Biocompatible and resorbable optical fibres emerge as promising technologies for in vivo applications like imaging, light delivery for phototherapy and optogenetics, and localised drug-delivery, as well as for biochemical sensing, wherein the probe can be implanted and then completely absorbed by the organism. Biodegradable waveguides based on glasses, hydrogels, and silk have been reported, but most of these devices rely on complex fabrication procedures. In this sense, this paper proposes a novel structured optical fibre made of agarose, a transparent, edible material used in culture media and tissue engineering. The fibre is obtained by pouring food-grade agar into a mould with stacked rods, forming a solid core surrounded by air holes in which the refractive index and fibre geometry can be tailored by choosing the agarose solution composition and mould design, respectively. Besides exhibiting practical transmittance at 633 nm in relation to other hydrogel waveguides, the fibre is also validated for chemical sensing either by detecting volume changes due to agar swelling/dehydration or modulating the transmitted light by inserting fluids into the air holes. Therefore, the proposed agarose-based structured optical fibre is an easy-to-fabricate, versatile technology with possible applications for medical imaging and in vivo biochemical sensing.

In this paper, the authors propose a state-of-the-art video shooting system for some randomly and quickly moving objects, which is based on our precise centering technology ‘1 ms Auto Pan-Tilt.’ It can capture the certain moving target as if it stopped and were fixed at the center of the image. In a previous study, we proposed and developed a handmade special device to control a camera gaze promptly, yet, it was not applicable for a real situation. This time, we remodeled the device as a unit with plural camera ports, which realized obtaining high-resolution movies. Moreover, with quantifying the system mathematically, we proposed a robust algorithm for a real use. Videos obtained by the new system help us grasp the detail movement of the target object more clearly, which is highly demanded in the realms of the measurement, astronomy, broadcasting service, and so on.

We report a liquid lens with a liquid–membrane–liquid structure in order to realize a variable-focus lens with a large optical aperture. We studied a typical liquid lens with a liquid–liquid structure and examined its physical limitation, namely, the capillary length, restricting the design of a larger-aperture liquid lens. We propose using elastic force instead of surface tension to acquire a much longer capillary length. We demonstrated that this approach can achieve sufficiently long capillary length when external pressure is loaded. A prototype lens with 30 mm aperture was constructed, and a resolution of 8.00 lp/mm was realized.