Abstract: An optical element for arrayed light source has a bar-like optical element and a light guide portion, which is a bar-like part formed on an incident portion side of the optical element portion, has a totally reflecting portion which causes emitted light from each of a plurality of LED that has an angle not less than a prescribed angle relative to an optical axis plane of the optical element portion to be totally reflected toward a plurality of concavo-convex reflecting portions provided between two LEDs adjacent to each other, the plurality of LEDs being arranged in a linear manner or an annular manner. The light guide portion guides, to the incident portion of the optical element portion, light reflected in each of the plurality of concavo-convex reflecting portions and emitted light that has an angle less than the prescribed angle.

Abstract: A package for light emitting element including a package main body 1 having a bottom face 7a on which a light emitting element 2 is arranged, and a concave portion 7 which is formed in an inverted truncated cone shape by an inner wall face 7b intersecting with the bottom face 7a with a predetermined angle, and a translucent member 6 filled in the concave portion 7 of the package main body 1, the angle between the inner wall face 7b composing the concave portion 7 and the bottom face 7a is selected within ±15° of the incident critical angle in which a direct light radiated from the light emitting element 2 undergoes total reflection at the interface between the translucent member 6 and air.

Abstract: A package for light emitting element including a package main body 1 having a bottom face 7a on which a light emitting element 2 is arranged, and a concave portion 7 which is formed in an inverted truncated cone shape by an inner wall face 7b intersecting with the bottom face 7a with a predetermined angle, and a translucent member 6 filled in the concave portion 7 of the package main body 1, the angle between the inner wall face 7b composing the concave portion 7 and the bottom face 7a is selected within ±15° of the incident critical angle in which a direct light radiated from the light emitting element 2 undergoes total reflection at the interface between the translucent member 6 and air.

Abstract: It is an object of this invention to overcome the problems of prior art by a unique arrangement based on a novel idea, and to provide an optical device having desired characteristics and an optical module and optical system incorporating the optical device. Provided is a photonic crystal including a three-dimensional periodic structure formed by using a first material which changes in properties relatively easily and a second material which does not change in properties relatively easily, wherein the first material is preferentially allowed to change in properties to make a refractive index difference between the first and second materials larger than that before the property change. Also provided is an optical device including a photonic waveguide, gain means, and reflecting means, wherein resonance is generated by reversing the propagating direction of light propagating in the photonic waveguide by the reflecting means while a gain is given to the light by the gain means.

Abstract: It is an object of this invention to overcome the problems of prior art by a unique arrangement based on a novel idea, and to provide an optical device having desired characteristics and an optical module and optical system incorporating the optical device. Provided is a photonic crystal including a three-dimensional periodic structure formed by using a first material which changes in properties relatively easily and a second material which does not change in properties relatively easily, wherein the first material is preferentially allowed to change in properties to make a refractive index difference between the first and second materials larger than that before the property change. Also provided is an optical device including a photonic waveguide, gain means, and reflecting means, wherein resonance is generated by reversing the propagating direction of light propagating in the photonic waveguide by the reflecting means while a gain is given to the light by the gain means.

Abstract: It is an object of this invention to overcome the problems of prior art by a unique arrangement based on a novel idea, and to provide an optical device having desired characteristics and an optical module and optical system incorporating the optical device.

Abstract: A surface emitting laser that provides an improved temperature characteristic, an improved optical output, and easy forming process. An optical communication system using this surface emitting laser is also provided. A surface emitting laser comprising: a substrate; a vertical cavity of layers formed on said substrate for propagating and resonating light along an axis vertical to a surface of said substrate, said light emitted from an active layer by current injection; and a reflective film disposed concentrically with the vertical axis around the outer periphery of said vertical cavity for reflecting the light from said active layer in a horizontal direction parallel to the surface of said substrate, the light emitted from said active layer forming a laser beam due to resonation, which laser beam is then emitted in a vertical direction. An optical communication system using the surface emitting laser.

Abstract: A transferred plasma heating anode for heating a molten metal in a container by applying Ar plasma generated by passing a direct current through the molten metal, the transferred plasma heating anode comprising; an anode, composed of a conductive metal, that has an internal cooling structure, a metal protector having an internal cooling structure that is placed outside the anode with a constant gap between the anode and the protector, and a gas supply means that supplies an Ar-containing gas to the gap, is characterized by the central portion on the external surface of the anode tip end being inwardly recessed.

Abstract: A surface emitting laser alleviated in reflection from facets of its active layer and waveguide layer and remarkably improved in oscillation property is configured not to make vertical side surfaces relative to the active layer or the waveguide direction. In VCSEL, side surfaces of the active layer are processed not to made vertical surfaces. In GCSEL, its crystalline surface orientation and its waveguide structure are chosen appropriately not to make upright surfaces on facets of the waveguide.

Abstract: In order to realize an optical functional device like a DFB laser in which the radiation mode loss is small and the threshold current is low even when high-order gratings easy to process are used, the gratings are configured to be asymmetric in its cross-sectional structure. Then, by partly varying the asymmetry (blaze angle) of the cross-sectional structure of the gratings along the cavity lengthwise direction, the cavity-lengthwise profile of radiation modes from the high-order gratings is controlled. It is also controlled by using a relationship between a phase shift of the gratings and the asymmetry. In a edge emitting DFB laser, by utilizing destructive interference among radiation modes, the radiation mode loss is reduced, and the threshold can be decreased. When a radiation mode is used as an output, the radiation mode can be reinforced to increase the output by utilizing constructive interference.

Abstract: A medium having the function of light emission or optical amplification induced by optical pumping is surrounded by an annular laser (ring laser) having a diffraction grating (holographic structure) of the second order or more. The output of the ring laser emits through this diffraction grating (holographic structure) and is extracted as radiation mode. This is used as pumping light to be input to the medium that is disposed in the vicinity of the center of the assembly. To stabilize the threshold of the longitudinal mode, which has a greater amount of radiation mode, a gain medium and a reflective structure could be further provided around the periphery of this ring laser. This element also plays a role of optical pumping from the sides of a VCSEL.

Abstract: First and second thin-film layers having different compositions are inserted between cladding layers to be stepped, and steps corresponding to a difference between the side etching amounts of these layers are formed. In this manner, symmetrical steps of about 0.5 &mgr;m can be reliably and easily formed on the side surfaces of a ridge waveguide.

Abstract: A transferred plasma heating anode for heating a molten metal in a container by applying Ar plasma generated by passing a direct current through the molten metal, the transferred plasma heating anode comprising; an anode, composed of a conductive metal, that has an internal cooling structure, a metal protector having an internal cooling structure that is placed outside the anode with a constant gap between the anode and the protector, and a gas supply means that supplies an Ar-containing gas to the gap, is characterized by the central portion on the external surface of the anode tip end being inwardly recessed.

Abstract: A surface emitting laser that provides an improved temperature characteristic, an improved optical output, and easy forming process. An optical communication system using this surface emitting laser is also provided. A surface emitting laser comprising: a substrate; a vertical cavity of layers formed on said substrate for propagating and resonating light along an axis vertical to a surface of said substrate, said light emitted from an active layer by current injection; and a reflective film disposed concentrically with the vertical axis around the outer periphery of said vertical cavity for reflecting the light from said active layer in a horizontal direction parallel to the surface of said substrate, the light emitted from said active layer forming a laser beam due to resonation, which laser beam is then emitted in a vertical direction. An optical communication system using the surface emitting laser.

Abstract: A distributed feedback laser comprising: waveguide (4) having a hologram (10) capable of emitting radiation mode light in upper and lower directions; first reflector (20) provided below said waveguide for returning said radiation mode light back to said waveguide; and second reflector (21A, 21B, 21C, 21D, 21E) provided above said waveguide for returning said radiation mode light back to said waveguide, intensity profile of said radiation mode light on said waveguide being non-uniform is disclosed. Also, by using 2nd- or higher-order diffraction gratings having an asymmetric cross-sectional configuration together with a reflection structure located at one side thereof, a highly directional optical isolator can be provided.

Abstract: Both an electric energy applying mechanism and an optical waveguide mechanism can be provided to an ITO layer (transparent electrode) by constituting an optical waveguide so as that the guided mode profile spread into the ITO layer. Also a bonding pad is provided to supply a power and apply an electric field onto the ITO layer. Accordingly, a device structure can be simplified and thus improvement in yield of the optoelectronic device having an optical waveguide and improvement in parameters of the optoelectronic device can be achieved.

Abstract: In a guiding structure having a corrugation, depth of the corrugation is changed in the axial direction to change the effective refractive index by a considerable amount. The use of a 2nd-order or higher-order corrugation is desirable to ensure precise processing. It is also desirable that changes in depth is continuous. In a DFB laser using this structure, effective phase shifting and optical confinement factor can be controlled by changing the depth of the corrugation. In a DFB laser/modulator integrating device commonly using an active layer and an absorption layer, changes of the corrugation in the axial direction, including the presence or absence thereof, can considerably change optical confinement factor to the absorption layer and the active layer.

Abstract: First and second thin-film layers having different compositions are inserted between cladding layers to be stepped, and steps corresponding to a difference between the side etching amounts of these layers are formed. In this manner, symmetrical steps of about 0.5 &mgr;m can be reliably and easily formed on the side surfaces of a ridge waveguide.

Abstract: It is an object of this invention to overcome the problems of prior art by a unique arrangement based on a novel idea, and to provide an optical device having desired characteristics and an optical module and optical system incorporating the optical device.

Abstract: A waveguide of an optical device is formed by a ridge waveguide portion which is formed as a substantially stripe convex portion extending in a guiding direction, and a gain waveguide portion which guides light in a gain region optically coupled with the ridge waveguide portion. An extended portion is formed to extend from the gain waveguide portion in the lateral direction of the waveguide. With this extended portion, an electrode and a pad are connected by a planar structure on the flat surface continuing from the upper surface of the ridge waveguide portion, without using any resin step. A phase shift effect is also obtained in the gain waveguide portion.