Self-aligned current aperture in native oxidized AlInAs buried heterostructure InGaAsP/InP distributed feedback laser

A InGaAsP/InP self-aligned, native oxidized buried heterostructure (BH) dis tributed feedback (DFB) laser is proposed. It is as easy to process as the ridge waveguide DFB laser and has superior performance. The current apertur e can be easily controlled without selective regrowth. The laser exhibits a low threshold of 5.0 mA with 36 dB side mode suppression ratio at the emis sion wavelength of 1.562 mu m. It emits in a single lobe with full width at half maximum angles of 33.6 degrees and 42.6 degrees for the lateral and v ertical fields, respectively. Its beam is more circular than that of the as -grown BH laser because the lower refractive index of oxide compared to the as-grown layer and results in a larger lateral optical confinement. Its ch aracteristic temperature (T-0) is 50 K at room temperature but increases in value at the higher temperature range. (C) 2000 American Institute of Phys ics. [S0003-6951(00)00812-3].