Design Of Photonic Crystal Semiconductor Lasers And Study Of Optical Properties Of Multi-quantum Wells In Active Layers

In the information society, semiconductor lasers are important optoelectronic devices. For the improvement of laser performance, photonic crystals(PCs) are introduced into the laser structures. PCs can control the propagation of light in laser devices, which improves the optical con? nement and feedback in lasers. In addition, the emission performance has been studied for strained and strain-compensated MQWs by photolumi-nescence at different excitation light power and lattice temperature. The polarization of gain of strain-compensated MQWs simpli?es the design of PCs used in the lasers. The results can be applied to optimize the design of semiconductor lasers.1. The dispersion relations of two dimensional triangular pattern PCs have been studied through plane wave expansion method. The photon energy band structure and photonic band gap mapping of PCs consisting of InP, InGaAsP materials have been calculated. From the mapping, the geometric parameters of PCs corresponding to different band gap frequencies can be speci?ed.2. Using the polarization of gain of strain-compensated MQWs, a ridge waveguide strain-compensated MQWs laser structure incorporated with photonic crystal mirror has been designed. Through plane-wave-based transfer-matrix method, the dependencies of the re? ectance spectra of photonic crystal mirror on symmetry direction, thickness, lattice constant and ?lling fraction are studied. The calculated results indicate the TE polarization light along FM direction is completely re?ected when the mirror is 2.6/um thick.3. The single transverse mode condition is studied for high power index-guided vertical-cavity surface-emitting laser incorporated with two dimensional triangular pattern PCs through the effective refractive index theory of one dimensional PCs and photonic crystal ?ber model. For DBR consisting of InGaAsP/InP material system, the critical ratio r/a (r: air hole radius, a: lattice constant) is 0.28in the case of a = 5jum and emission area formed by a single point-defect and the ratio is 0.10 in the case of a = 3/um and emission area formed by seven point-defect.4. The luminescent properties of strained InAsP/InP and strain-compensated InAsP/InGaAsP MQWs are studied by the photoluminescent spectra at different excitation light power and lattice temperature. The experimental results indicate the superior temperature stability of luminescent ef? ciency for strain-compensated MQWs, for which the luminescent ef? ciency decreases to 90% when the temperature increases to 150K, but 50K for strain MQWs. So the semiconductor laser with strain-compensated MQWs as active layers can operate at higher temperature than that strained one.