Abstract: Provided is a micro-needle array in which all fine needles can be more easily inserted into the skin regardless of positions where the fine needles of the micro-needle array are located on a substrate. The micro-needle array includes: a substrate; and a plurality of micro-needles arranged on one surface of the substrate. Tip parts of the plurality of micro-needles have a height difference, and the micro-needles have a needle length of 80 ?m or more and 2000 ?m or less. The height difference of the plurality of micro-needles is preferably based on unevenness of the substrate.

Abstract: The present invention solves a problem that it is difficult for a microneedle located in a central portion of a microneedle array to be inserted into a skin. A microneedle array including a substrate and a plurality of microneedles arranged vertically and horizontally on one face of the substrate, wherein a needle interval of the microneedles is different in a peripheral portion and in a central portion of the substrate, and a needle density of the microneedles is different in the peripheral portion and in the central portion of the substrate. It is preferable that the needle density of the microneedles is sparser in the central portion than in the peripheral portion of the substrate, and the needle interval of the microneedles is wider in the central portion than in the peripheral portion of the substrate.

Abstract: The invention discloses a light modulator comprising a semiconductor substrate, a curved thin-film semiconductor optical waveguide having a predetermined curvature and, semiconductor electrode layers formed contiguous to the waveguide, whereby when a potential is applied across the electrode layers, the carrier density in the regions adjacent the waveguide may be varied and consequently the radiation loss in the curved waveguide may be varied accordingly to modulate light radiating through the waveguide in response to the electric potential applied across the electrode layers.

Abstract: The impurity concentration distribution of the layers of a multilayer junction diode is varied such that the concentration in a first region contiguous to the junction is low, in a second region is high, in a third region is low and in a last region gradually increases in the direction away from the junction.