A wavelength conversion element includes a wavelength conversion layer containing a plurality of phosphor particles and an inorganic binder that bonds the phosphor particles to each other and a substrate that holds the wavelength conversion layer and contains alumina and air cavities. The substrate has an apparent air cavity ratio that is greater than or equal to 10% and smaller than or equal to 30%. The substrate has a median diameter of particles of the alumina that is greater than or equal to 0.1 m and smaller than or equal to 1.0 m.

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.

Occurrence of luminance unevenness or color unevenness is efficiently reduced. In a light-emitting part (10), a first phosphor layer (La1) containing a first YAG phosphor (3), and a second phosphor layer (La2) containing a second YAG phosphor (2) are stacked on a substrate (1). A particle size of the first YAG phosphor is smaller than a particle size of the second YAG phosphor. The first phosphor layer is arranged on a side far from the substrate, and excitation light (E1) is incident on the first phosphor layer.

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.

An optical semiconductor component package includes a base, a frame, a lid, and a light absorbing member located on an inner surface of the lid. The base is plate-like and has a first surface including a mount area in which an optical semiconductor component is mountable. The frame is located on the first surface and surrounds the mount area. The lid is plate-like and is bonded to the frame and covers the mount area. The light absorbing member is located on a second surface of the lid facing the mount area, and has a plurality of recesses on its surface.

A laser system includes first and second mirrors, a semiconductor laser and a high frequency pulse generator. The semiconductor laser generates optical power within an optical cavity and reflects the optical power between the first mirror and second mirrors. The optical power has a frequency of f.sub.original-laser. The high frequency pulse generator generates a high frequency pulse with a rise time greater than an optical cycle of the optical power within the optical cavity and directly impinges the high frequency pulse on the optical power within the optical cavity. Impinging the high frequency pulse on the optical power within the optical cavity causes a frequency shift of the optical power to generate a final laser frequency that is greater than f.sub.original-laser as well as beyond a frequency band of the second mirror to cause a final laser to be emitted past the second mirror and from the semiconductor laser.