Transistor Laser With a Current Confinement Aperture in the Emitter Ridge

We propose a transistor laser with a current confinement aperture (a-TL) formed in a reverse junction layer in the middle of emitter ridge. The a-TLs are studied numerically in comparison with the deep ridge TLs. Data show that in a-TLs, the effects of nonradiative recombination centers on the side walls of the emitter ridge can be reduced greatly due to the confinement of carrier flow in the center region of the emitter ridge. Furthermore, the reverse junction layer can be used as an etching stop layer for the emitter ridge formation, which facilitates both the design and the fabrication of the device. Together with the fact that in a-TLs, the effects of p-type material are alleviated effectively by placing the multi-quantum wells above the base layer, high performance can be expected, especially for long-wavelength devices.