Abstract: A light emitting device has a resonant cavity LED (RCLED) (1) within encapsulation (24). The encapsulation has a convex spherical surface (26) forming a lens for emitted light. The diode's cavity (14, 15, 16) is of a length to provide detuning of 20 nm for an emission wavelength of 650 nm. A relatively flat thermal response is achieved.

Abstract: VCSEL diode comprises a bottom electrode (10), conducting substrate material (11), a bottom mirror (12) formed by a multilayer distributed Bragg reflector (DBR) of certain conductivity and reflectivity RA, and an active region (13) comprising a plurality of layers some of which are quantum wells. It also comprises a top mirror (14) formed by a multilayer distributed Bragg reflector (DBR) with reflectivity RB<RA and conductivity of a second type. There are a number of layers (15, 18) which through a process of selective oxidation (exposure to a high temperature wet atmosphere) may be selectively converted to oxide layers, therefore producing well defined internal oxide apertures within the top mirror. There is a high-conductivity semiconductor top contact layer (17), a top electrode layer (19) with a centrally located aperture from which light is emitted, and a trench (16) which defines a mesa type VCSEL.

Abstract: A green LED has a substrate, a GaN heavily n-doped bottom confining layer, an active region, an upper GaN confinement layer, and a semi-transparent ohmic contact layer. The active region has less than or equal to three highly compressively strained quantum wells. The widths of the quantum wells is less than 3 nm. The active region arrangement provides a short free carrier life-time and hence an increase in the modulation bandwidth of the LED.