Polarization- and angle-independent, dual-band metasurface thermal emitter was developed. The metasurface emits radiation at 4.26 μm and 3.95 μm, conventionally used for CO2 sensing. The metasurface is based on a planar Au/Al2O3/Au structure, in which orthogonal rectangular Au patches are arrayed alternately, and generates nearly perfect blackbody radiation with an emittance as high as 0.97. The metasurface is integrated on a resistive heater mounted on a SiN membrane, so that the infrared waves are produced by applying a voltage. The metasurface emitter was incorporated into an actual CO2 sensing system and was demonstrated to reduce the electric power needed by about 30% compared with a conventional blackbody emitter by suppressing unnecessary radiation.

We have demonstrated thermal emission of linearly polarized and narrow-band midinfrared waves from subwavelength gratings of narrow and deep rectangular cavities engraved on a Au surface. 100-nm-wide and 1000-nm-deep, high-aspect trenches were accurately manufactured by inversion from master molds. Organ pipe resonance of surface plasmons in the cavities exhibits a Lorentzian emission peak centered at 2.5–5.5μm. The maximum emittance reaches 0.90 and the peak width Δλ∕λ is as narrow as 0.13–0.23. This simple emitter is expected to play a key role in the infrared sensing technologies for analyzing our environment.

We have demonstrated that orthogonally polarized two-color infrared waves thermally emitted from gratings integrated onto a single Au chip open a way for simple and efficient chemical analysis. Each component grating is made of high-aspect cavities with a width on the order of 100nm and a depth close to 1μm, and generates linearly polarized and narrow-band midinfrared light by the organ pipe resonance of surface plasmons. Effectiveness of the integrated grating emitters for nondispersive infrared analysis has been shown on the basis of a model experiment for determining the concentration of a specific chemical compound in liquids.

There is a great demand for the highly accurate and reliable arrangement of micro objects smaller than 100 p in order to construct micro devices. Since micro objects tend to adhere to other objects by electrostatic force, it is possible to pick them up easily by contact with a needle tip instead of grasping by tweezers. On the other hand, it is difficult to place them on a substrate. To solve this problem, we have proposed a handling method by controlling the contact face area, i.e. picking up the object by contact with the center of the tool-tip plane, and placing it by contact with the edge and also inclining the tool. However, it is difficult to execute this operation by manual control, because it requires delicate movement by the manipulator, in order not to break the object or flip it away. In this study, we automate this pick-andplace operation by visual and force control. Moreover, to arrange micro objects with high accuracy and reliability, all necessary functions such as calibration, object search, and positioning are integrated, and an automatic handling system is constructed. We successfully demonstrated a completely automatic arrangement of several micro objects of 30 pn in diameter under SEM monitoring.

Optical patch antennas sandwiching dielectrics between metal layers have been used as deep subwavelength building blocks of metasurfaces for perfect absorbers and thermal emitters. However, for applications of these metasurfaces for optoelectronic devices, wiring to each electrically isolated antenna is indispensable for biasing and current flow. Here we show that geometrically engineered metallic wires interconnecting the antennas can function to synchronize the optical phases for promoting coherent resonance, not only as electrical conductors. Antennas connected with optimally folded wires are applied to intersubband infrared photodetectors with a single 4-nm-thick quantum well, and a polarization-independent external quantum efficiency as high as 61% (responsivity 3.3 A W −1 , peak wavelength 6.7 μm) at 78 K, even extending to room temperature, is demonstrated. Applications of synchronously wired antennas are not limited to photodetectors, but are expected to serve as a fundamental architecture of arrayed subwavelength resonators for optoelectronic devices such as emitters and modulators.