Abstract: An optical waveguide element includes: a substrate on which an optical waveguide is formed; and an electrode that is formed on the substrate and controls a light wave propagating through the optical waveguide. The optical waveguide includes a protruding portion extending on the substrate, and the electrode includes a base layer made of Nb, and an upper layer formed on the base layer, the base layer being formed between the substrate and the upper layer.

Abstract: Provided is an optical waveguide element that prevents damage to a substrate and improves productivity. In an optical waveguide element in which an optical waveguide (24, 23) is formed on a substrate 1, a groove portion 3 is formed in at least a part of the substrate along an outer periphery 10 of the substrate 1.

Abstract: A planar illumination device according to an embodiment includes a light source and a light guide plate. The light source emits light in a predetermined direction. The light guide plate includes a side surface, an emission surface as one of principal surfaces, and a back surface as the other principal surface, the back surface including a prism formed thereon, the prism emitting, through an emission surface, light emitted from the light source and entered from the side surface. The prism includes, at a section parallel to the predetermined direction, a first region substantially parallel to the emission surface and a second region tilted relative to the emission surface, the first region and the second region extending in a direction oblique to the predetermined direction.

Abstract: A planar lighting device according to an embodiment includes a light guide plate and a reflecting member. The light guide plate has an incident surface that receives light output from a light source and an output surface that outputs the light received by the incident surface. The reflecting member faces an end surface opposite to the incident surface of the light guide plate and reflects light leaking from the end surface. A plurality of first prisms are formed on an opposite surface opposite to the output surface-of the light guide plate to be away from the output surface stepwise from the incident surface to the end surface.

Abstract: A vehicle lamp includes a projection lens, a first light source disposed behind the projection lens and configured to emit light forming a low-beam light distribution pattern which is a predetermined light distribution pattern, a reflector configured to reflect light emitted from the first light source toward a first rear focal point of the projection lens, and a second array light source disposed behind the projection lens and having a plurality of semiconductor light emitting elements arranged in at least one row. The second array light source is configured to emit light forming an additional light distribution pattern, and the center position or maximum light intensity position of the additional light distribution pattern overlaps with the low-beam light distribution pattern on a virtual vertical screen in front of the lamp.

Abstract: A planar lighting device according to an embodiment includes a light guide plate and a reflecting member. The light guide plate has an incident surface that receives light output from a light source and an output surface that outputs the light received by the incident surface. The reflecting member faces an end surface opposite to the incident surface of the light guide plate and reflects light leaking from the end surface. A plurality of first prisms are formed on an opposite surface opposite to the output surface-of the light guide plate to be away from the output surface stepwise from the incident surface to the end surface.

Abstract: An optical modulator having a substrate having an electro-optic effect, an optical waveguide formed in the substrate, and a signal electrode and ground electrodes formed on the substrate so as to interpose the optical waveguide, in which the signal electrode and the ground electrodes respectively have a plurality of electrode layers, and an interval between the signal electrode and the ground electrode is larger than a mode field diameter of the optical waveguide in a first layer of the electrode layers closest to the substrate and is smaller than the interval in the first layer of the electrode layers in at least any one of second and upper layers of the electrode layers.

Abstract: A lamp unit includes a light-emitting element array composed by a plurality of light-emitting elements, having respective individual irradiation regions constituting a high-beam light-distribution pattern and configured to be capable of being turned on individually, mounted in array on a substrate, a projection lens disposed in front of the light-emitting element array, and a reflector disposed below the light-emitting element array. Inter-light-emitting-element spacing within the light-emitting element array widens the more separated the elements are from the projection lens' optical axis.

Abstract: A vehicle lamp includes a projection lens, a first light source disposed behind the projection lens and configured to emit light forming a low-beam light distribution pattern which is a predetermined light distribution pattern, a reflector configured to reflect light emitted from the first light source toward a first rear focal point of the projection lens, and a second array light source disposed behind the projection lens and having a plurality of semiconductor light emitting elements arranged in at least one row. The second array light source is configured to emit light forming an additional light distribution pattern, and the center position or maximum light intensity position of the additional light distribution pattern overlaps with the low-beam light distribution pattern on a virtual vertical screen in front of the lamp.

Abstract: A lamp unit includes a light-emitting element array composed by a plurality of light-emitting elements, having respective individual irradiation regions constituting a high-beam light-distribution pattern and configured to be capable of being turned on individually, mounted in array on a substrate, a projection lens disposed in front of the light-emitting element array, and a reflector disposed below the light-emitting element array. Inter-light-emitting-element spacing within the light-emitting element array widens the more separated the elements are from the projection lens' optical axis.