Characteristics Analysis Of GaAs Based High Power Semiconductor Laser And High Brightness LED

As the most important part of the optoelectronics industry, semiconductor laser has become one of the most prospective products after the large-scale integrated circuits. Semiconductor light emitting diode (LED) is the key displaying device of semiconductor optoelectronics. Serious problem of heat-production in the normal high power semiconductor laser, especially the catastrophic optical damage near the light-emitting surface of cavity and the joule heat damage produced when LED is working under a large current, have limited the improvement of its light output power. Besides, its worse equality of light beam compared to the solid state laser and its low emitting efficiency also have a great influence on the working characteristics of semiconductor laser and narrow its latent applications. The normal high brightness LED also faces the same problem of heat-production when working under a large current. Another factor limiting the brightness of the normal high brightness LED is the high cost and the complexity of the present key technologies. To GaAs based high power laser, a detailed analysis of the mechanism and significance of the novel QW laser with multiple active layers cascaded by tunneling diodes brought forward by professor Shen Guangdi is firstly made. The novel QW laser with multiple active layers cascaded by tunneling diodes has broken the restriction that internal quantum efficiency of normal laser is less than 1, and can multiply the internal quantum efficiency without changing working current. Thus light output power is increased but the joule heat is almost the same. At the same time, the mechanism of multiple active layers coupled by tunneling diodes can remarkably increase the emitting area, enhance the COD level, improve the symmetry of far field, and benefit the mode stability. Secondly, the characteristics of the tunneling diode, which is the important part of this mechanism, is also measured and analyzed. And the effects of inducing the tunneling diode to the laser are stressed. Then, the optical, æ¡°II? electrical and calorific characteristics of the C-doped normal InGaAs SQW laser LD8 and the C-doped novel InGaAs QW laser LD 11 with double active layers and the C- doped novel InGaAs QW lasers LD12, LDI3, LD14 with triple active layers are measured and analyzed. Our 1 OO~m broad-stripe ridged light-etching ridged structures has achieved very high efficiencies, and the internal quantum efficiencies of the novel QW lasers with double active layers and triple active layers cascaded by tunneling diodes have exceeded 1. Thus, the feasibility of the novel QW laser with multiple active layers cascaded by tunneling diodes is validated. Comparisons between the high performance normal C-doped InGaAs SQW laser and novel C- doped InGaAs QW laser with multiple active layers cascaded by tunneling diodes are also made, with a view to the problems in novel C-doped InGaAs QW laser with multiple active layers cascaded by tunneling diodes. At last, the laser preparing process is simply introduced, and some problems in it are discussed. Particularly the threshold characteristics of the novel QW laser with multiple active layers cascaded by tunneling diodes are analyzed and deduced based on the threshold analysis of normal C-doped InGaAs SQW laser. The computing results are well consistent with the measuring results. Our deep-etching technology can get very low threshold current. The threshold current of the deep-etching striped novel laser can b...