A wavelength converter 100 includes: a first phosphor 1 composed of an inorganic phosphor activated by Ce.sup.3+; and a second phosphor 2 composed of an inorganic phosphor activated by Ce.sup.3+ and different from the first phosphor. At least one of the first phosphor and the second phosphor is particulate. The first phosphor and the second phosphor are bonded to each other by at least one of a chemical reaction in a contact portion between the compound that constitutes the first phosphor and a compound that constitutes the second phosphor and of adhesion between the compound that constitutes the first phosphor and the compound that constitutes the second phosphor.

A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the light-emitting layer has an at least five-period multiple quantum well structure, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

A vertical cavity surface emitting laser (VCSEL) has first and second electrical contacts, and an optical resonator. The optical resonator has first and second distributed Bragg reflectors (DBRs), an active layer, a distributed heterojunction bipolar phototransistor (DHBP), and an optical guide. The DHBP has a collector layer, light sensitive layer; a base layer; and an emitter layer. There is an optical coupling between the active layer and the DHBP for providing an active carrier confinement by the DHBP. The optical guide guides an optical mode within the optical resonator during operation. The optical guide is outside a current flow which can be provided by the first and second electrical contacts during operation of the VCSEL. The optical guide is outside a layer sequence between the first and second electrical contacts in the vertical direction of the VCSEL. The optical guide has an oxide aperture arranged in the second DBR.

An optical member includes: a main body having transparency or heat dissipation properties; an optical film disposed on an upper face of the main body; a metal film disposed on the upper face of the main body in a region other than a region where the optical film is disposed; a surrounding part joined via the metal film; and a wavelength conversion part surrounded by the surrounding part. The wavelength conversion part is positioned inward of a periphery of the optical film in a top view. The wavelength conversion part is not directly bonded to the optical film and the main body.

A wavelength converting element according to the present disclosure includes: a wavelength converting body including an incident surface and an exit surface and configured to perform wavelength conversion on a primary light in a first wavelength band, entered from the incident surface, thereby generating a secondary light in a second wavelength band, which differs from the first wavelength band, the wavelength converting body emitting the secondary light from the exit surface; a metallic antenna group provided in a close vicinity of the wavelength converting body and including a plurality of metallic antennas disposed so as to be spaced apart from each other at a distance of substantially an optical wavelength of the secondary light in the wavelength converting body; and a dielectric antenna group including a plurality of dielectric antennas and provided so as to face the exit surface of the wavelength converting body.

The present invention relates to an apparatus for damping arid monitoring emissions from a light emitting device, particularly a vertical cavity surface emitting laser (VCSEL), comprising: a semi transparent substrate, preferably glass; a light emitting device for generating light emission; a damping layer deposited on a surface of the substrate; and a pair of electrodes, each of which being in direct contact with the damping layer. The damping layer is adapted to decrease the power level of the light emission of the light emitting device by absorption, to a desired level, for instance, to a level that meets eye safety limits. In addition, the damping layer is photosensitive to the light emission of the light emitting device, thereby allowing the pair of electrodes to output an electric signal corresponding to the power level of the light emission of the light emitting device.

A method of an optical member comprises: providing a light transmissive member or a heat dissipating member in which a metal film and an optical film having a larger thickness than a thickness of the metal film are formed in separate regions of an upper face of a main body of the light transmissive member or an upper face of a main body of the heat dissipating member, providing a wavelength conversion member in which a metal film is formed on a lower face of a main body of the wavelength conversion member, and bonding the metal film of the light transmissive member or the metal film of the heat dissipating member to the metal film of the wavelength conversion member via a metal adhesive while positioning the optical film directly under a wavelength conversion part of the wavelength conversion member.

A method for increasing the bandwidth of an electroabsorption modulator (EAM) includes the following steps. First, a plurality of p-i-n active waveguides for the EAM are defined on a p-i-n optical waveguide forming an EAM having a shorter p-i-n active waveguide length. Then, the bandwidth of the EAM can be increased. Second, the high-impedance transmission lines are used in series to connect the EAM sections to reduce the microwave reflection and then increase the device bandwidth. Finally, the impedance-controlled transmission lines for the signal input and output can not only reduce the parasitic effects resulting from packaging, but also reduce the microwave reflection resulting from the impedance mismatch at the device input and load.

The laser device includes a substrate, a laser element disposed on the substrate for emitting a laser light ray, a light guide member disposed on the substrate, and a wavelength conversion layer. The light guide member is light-transmissible and thermally conductive, and has at least one reflection surface for reflecting the laser light ray from the laser element so as to change travelling direction of the laser light ray. The wavelength conversion layer converts wavelength of the laser light ray from the light guide member to result in a laser beam, and contacts the light guide member so that heat from the wavelength conversion layer is transferred to the substrate through the light guide member.

The laser device includes a substrate, a laser element disposed on the substrate for emitting a laser light ray, a light guide member disposed on the substrate, and a wavelength conversion layer. The light guide member is light-transmissible and thermally conductive, and has at least one reflection surface for reflecting the laser light ray from the laser element so as to change travelling direction of the laser light ray. The wavelength conversion layer converts wavelength of the laser light ray from the light guide member to result in a laser beam, and contacts the light guide member so that heat from the wavelength conversion layer is transferred to the substrate through the light guide member.