Graded-index strained multiquantum-well GaInAsP lasers grown by gas-source molecular-beam epitaxy: Growth and characterization

We have grown graded‐index strained multiquantum‐well GaInAsP lasers by gas‐source molecular‐beam epitaxy (GSMBE) for a wavelength of 1.47 μm. The growth of graded layers and quantum wells by GSMBE is reported. X‐ray diffraction measurements of the laser structure were made and a simulation by dynamical diffraction theory gave good fitting. The threshold current densities were measured for 400‐ and 1000‐μm‐long broad‐area lasers, and they were 1350 and 780 A/cm2, respectively. We have also fabricated ridge waveguide lasers from the same sample.