Leaky waveguide laser diodes for advanced manufacturing and metrology

摘要

We have successfully designed and prepared gain-guided high -power 1.3-1.55 μm leaky waveguide (LWG) laser diodes, taking into account their loss mechanisms such as Auger electron non-radiative recombination, carrier leakage over the heterobarrier, and inter-valence-band absorption etc. This is the first time to incorporate the leaky waveguide structure into the quaternary III-V compounds in order to obtain in long wavelength region high power laser diodes for advanced manufacturing and metrology. In this work we have shown that the incorporation of the leaky waveguide structure into the material system would reduce the threshold current density and alleviate the loss mechanisms. This would result in a reduction in lasing threshold current and an improvement in the temperature sensitivity. It was grown by a unique liquid phase epitaxy (LPE) and was modified by growing an intrinsic InGaAsP waveguiding layer which replaced its n-type counterpart as in usual large optical cavity devices and provided a higher temperature stability than that of conventional DH lasers. Using the LWG structure, we have obtained 1.55 μm laser diodes with threshold currents comparable to common lasers (J_(th)≤2.7 KA/cm~(2)) but with the characteristic temperature T_(O) near to those of GaAs-AlGaAs lasers (140K). Especially, we have attained the peak output powers up to higher than 2W per facet in pulsed operation at room temperature.