Abstract:
A semiconductor light emitting device, such as the light emitting diode (LED) or the laser diode (LD), having a structure in which a light emitting area is a double heterostructure or a multi-layer quantum well structure. The light emitting area is formed on a substrate. Subsequently, an electrically conductive oxide layer as a transparent window layer to eliminate the crowding effect is formed on the light emitting area. The substrate layer consists of a GaAs substrate and a GaAsP layer to increasing the band gap energy of the substrate. The electrically conductive oxide layer is formed of AlZnO(x) material, having a lower electrical resistivity and a high transparency in the visible wavelength region. The window layer is formed using a physical vapor deposition or a metalorganic chemical vapor deposition.
Abstract:
A structure of a semiconductor light emitting device includes a GaAs substrate, a GaAsP interface substrate, a first cladding layer, an active layer, and a second cladding layer. The GaAsP interface substrate layer is formed on the GaAs substrate, in addition, the GaAsP interface substrate layer formed on the substrate is of a thickness such that the upper surface of the GaAsP interface substrate layer adjacent to the substrate is composed of single crystal. The first cladding layer of a first conductivity is formed on the GaAsP interface substrate layer. The active layer is formed on the first cladding layer, from which the light is generated in the active layer. The second cladding layer of a second conductivity is formed on the active layer.
Abstract:
A light emitting diode includes a semiconductor substrate of a first conductivity type. A first electrode is formed on a part of the substrate. A reflection stack of the first conductivity type is formed on the substrate. An active layer is then formed on the reflection stack. An anti-reflection stack of a second conductivity type is grown on the active layer, and the anti-reflection stack consists of a plurality of layers, wherein each layer has a thickness of (m+1).lambda./2, where m is zero or a positive integer and .lambda. is a wavelength of radiation generated by the active layer. A window layer of the second conductivity type is formed on the anti-reflection stack. A second electrode is then formed on a part of the window layer.
Abstract:
An apparatus for amplifying differential signals is provided. The apparatus comprises a differential amplifier, a first impedance component, a second impedance component, a voltage source and a high-pass filter. The differential amplifier receives an input differential signal with a first terminal and a second terminal. The differential amplifier also drains currents from the voltage source into a third terminal and a fourth terminal via the first and the second impedance components respectively. The high-pass filter receives the input differential signal and outputs a control differential signal to control the first and the second impedance components so that the impedance of the first and the second impedance components vary inversely in response to the voltages at the first and the second terminals respectively when the state of the input differential signal changes.
Abstract:
An apparatus for amplifying differential signals is provided. The apparatus comprises a differential amplifier, a first impedance component, a second impedance component, a voltage source and a high-pass filter. The differential amplifier receives an input differential signal with a first terminal and a second terminal. The differential amplifier also drains currents from the voltage source into a third terminal and a fourth terminal via the first and the second impedance components respectively. The high-pass filter receives the input differential signal and outputs a control differential signal to control the first and the second impedance components so that the impedance of the first and the second impedance components vary inversely in response to the voltages at the first and the second terminals respectively when the state of the input differential signal changes.