Abstract: A laser capable of emitting multiple laser beams is provided. A two-dimensional photonic crystal laser according to the present invention has a laminated structure including an active layer, a first photonic crystal layer having a periodic distribution of refractive index with a first period, and a second photonic crystal layer having a periodic distribution of refractive index with a second period that differs from the first period. This two-dimensional photonic crystal laser can emit a main beam traveling in a direction perpendicular to the two-dimensional photonic crystals and side beams each traveling in a direction inclined with respect to the main beam. These beams can be used, for example, in a recording/reproducing device by means of an optical disk, the main beam being used for recording/reproducing information and the side beams for following up the track.

Abstract: The present invention relates to a surface plasmon resonance sensor which has a first dielectric layer, a metal layer disposed on the first dielectric layer, and a second dielectric layer covering the metal layer. The surface plasmon resonance sensor includes: a sensor main body provided with an opening for exposing a part of a surface of the metal layer on a side facing the second dielectric layer, and for allowing a measurement sample to be brought into contact with this surface; a light source for introducing a beam into the metal layer from one end of the metal layer in a longitudinal direction of the metal layer; and a detection unit detecting a beam emitted from the other end of the metal layer, has high sensitivity in measurement, is downsized, and is usable in a simple manner.

Abstract: There is provided an organic electroluminescence device including of a substrate, an anode layer, an organic layer including at least one organic material and a cathode layer. A primary light outgoing direction of the device is parallel to a surface of the substrate. Any one of cutoff wavelengths in a transverse electric mode of an optical waveguide having a core layer partially formed of the organic layer is within a wavelength range of a full width at half maximum of a fluorescence spectrum of any one of the organic materials included in the organic layer.

Abstract: One objective of the present invention is to provide a laser device which is capable of scanning beams of a laser light of high output power at a high speed without using mechanical scanning mechanisms. A plurality of the upper electrodes 33 is linearly arranged in the photonic crystal laser provided with an active layer 21 and a two-dimensional photonic crystal layer 23 which are held between upper electrodes 33 and a lower electrode 27. A current is introduced from one upper electrode 33 or the plurality of the upper electrodes 33 disposed adjacently. Therefore, the active layer 21 generates light and the light is intensified by diffraction in the two-dimensional photonic crystal layer 23, so that a stronger laser light is emitted to the outside from around the upper electrodes 33 into which a current is introduced. When the current-injected upper electrodes are sequentially switched, a laser light scan is performed in the direction of the array of the upper electrodes.

Abstract: The two-dimensional photonic crystal surface emitting laser according to the present invention includes a semiconductor substrate, a main laser section and a reflection film. The main laser section includes a lower cladding layer, an active layer, a two-dimensional photonic crystal layer, an upper cladding layer and a contact layer, which are all deposited on the semiconductor substrate. The reflection film, which surrounds the entire side surfaces of the main laser section, is made of a thin titanium-gold film deposited by sputtering.

Abstract: The two-dimensional photonic crystal surface emitting laser according to the present invention includes a number of main modified refractive index areas periodically provided in a two-dimensional photonic crystal and secondary structures each relatively located in a similar manner to each of the main modified refractive index areas. The location of the secondary structure is determined so that a main reflected light which is reflected by a main modified refractive index area and a secondary reflected light which is reflected by a secondary structure are weakened or intensified by interference.

Abstract: A surface-emitting laser according to the present invention includes a laminated body between a first electrode 471 and a second electrode 472. The laminated body includes an active layer 43 and a two-dimensional photonic crystal 45. The first electrode 471 is ring shaped. A voltage is applied between the first and second electrodes 471 and 472 to supply an electric current into the active layer 43 and thereby cause an emission of light. Since the first electrode 471 is ring shaped, the light thereby generated has a ring-shaped field distribution within the two-dimensional photonic crystal 45. Due to this field distribution, a radially polarized laser beam having a ring-shaped cross section is emitted from the two-dimensional photonic crystal 45. The laser beam thus generated can be focused by a focusing lens to make its diameter smaller than the diffraction limit. Such a laser beam is suitable for optical pickups and other optical devices.

Abstract: A two-dimensional photonic crystal LED composed of a p-type semiconductor cladding layer 12, an active layer 11 of light-emitting material, and an n-type semiconductor cladding layer 13 placed between a pair of electrodes, where air holes 16 penetrating through the layers 12, 11 and 13 and arranged periodically in the layers 12, 11 and 13 are provided. At least a part of the inner wall of the air holes 16 is oxidized 17 in either one or both of the p-type semiconductor cladding layer 12 and the n-type semiconductor cladding layer 13. The holes and electrons injected from the electrodes avoid the oxidized region 17 and enter the active layer 11 apart from the air holes 16, which minimizes the recombination (surface recombination) of the holes and electrons producing heat instead of light.