Growth and characterization of GSMBE grown strained InGaAs/InGaAsP structures for MQW lasers at 2.0 μm

We report on the growth, characterization and performance of compressively strained In_0.75Ga_0.25As/InGaAsP (λ_g=1.3 μm) MQW structures on InP substrates for laser diodes in the 2.0-2.1 μm range. These laser wafers were grown by gas source molecular beam epitaxy (GSMBE) for the first time. Both broad area and ridge-waveguide structure lasers have been fabricated and evaluated. The electrical and optical properties of high quality InGaAsP, corresponding to the band wavelength of 1.3 μm, have been investigated in detail. The properties of InGaAsP layers have a sensitive dependence on the growth temperature. With the optimization of growth conditions, high quality InGaAsP layers with narrow double-crystal X-ray diffraction rocking curve (DCXRC) and PL FWHM, and high Hall mobility have been obtained. The EL at room temperature of broad-area InGaAs/InGaAsP strained MQW laser structures have shown a peak wavelength of 1.98 μm, indicating the precise control of material composition and layer thickness. Pulsed lasing at 77 K has been achieved under an injection current of 70 mA for the ridge waveguide structure of laser diodes and the FWHM of the spectrum is 5.3 nm with peak at 1.816 μm