Time-dependent thermal simulation of ridge-geometry InGaN laser diodes is carried out with a two-dimensional model. A high temperature in the waveguide layer and a large temperature step between the regions under and ...Time-dependent thermal simulation of ridge-geometry InGaN laser diodes is carried out with a two-dimensional model. A high temperature in the waveguide layer and a large temperature step between the regions under and outside the ridge are generated due to the poor thermal conductivity of the sapphire substrate and the large threshold current and voltage. The temperature step is thought to have a strong influence on the characteristics of the laser diodes. Time-resolved measurements of light-current curves,spectra, and the far-field pattern of the InGaN laser diodes under pulsed operation are performed. The results show that the thermal lensing effect improves the confinement of the higher order modes and leads to a lower threshold current and a higher slope efficiency of the device while the high temperature in the active layer results in a drastic decrease in the slope efficiency.展开更多
A desiga of arbitrary waveform generator using NI PXI- 5412 module （an arbitrary waveform generator） was provided in this paper, based on virtual instrument technology and LabVIEW. The generator can produce standard...A desiga of arbitrary waveform generator using NI PXI- 5412 module （an arbitrary waveform generator） was provided in this paper, based on virtual instrument technology and LabVIEW. The generator can produce standard function waveforms, such as sine, triangle, square wave with adjustable amplitude and frequency. It can also produce arbitrary waveforms of different data files importing by Analog Waveform Geaemtor Software. A heart dectric wavefonn was set as an example of arbitrary waveform generation. It has practical value, because the standard functions and heart electric waveforms generated by the generator can be used in laboratories.展开更多
文摘Time-dependent thermal simulation of ridge-geometry InGaN laser diodes is carried out with a two-dimensional model. A high temperature in the waveguide layer and a large temperature step between the regions under and outside the ridge are generated due to the poor thermal conductivity of the sapphire substrate and the large threshold current and voltage. The temperature step is thought to have a strong influence on the characteristics of the laser diodes. Time-resolved measurements of light-current curves,spectra, and the far-field pattern of the InGaN laser diodes under pulsed operation are performed. The results show that the thermal lensing effect improves the confinement of the higher order modes and leads to a lower threshold current and a higher slope efficiency of the device while the high temperature in the active layer results in a drastic decrease in the slope efficiency.
基金supported by Research Project of "SUST Spring Bud"from Shandong University of Science and Technology(No.2008BWZ042)
文摘A desiga of arbitrary waveform generator using NI PXI- 5412 module （an arbitrary waveform generator） was provided in this paper, based on virtual instrument technology and LabVIEW. The generator can produce standard function waveforms, such as sine, triangle, square wave with adjustable amplitude and frequency. It can also produce arbitrary waveforms of different data files importing by Analog Waveform Geaemtor Software. A heart dectric wavefonn was set as an example of arbitrary waveform generation. It has practical value, because the standard functions and heart electric waveforms generated by the generator can be used in laboratories.
