A new polarization-insensitive 1.55-μm InGaAs(P)-InGaAsP multiquantum-well electroabsorption modulator using a strain-compensating layer

In a conventional polarization-insensitive multiquantum-well electroabsorption modulator, it is normal to apply tensile and compressive strain on the well and the barrier, respectively. But the main disadvantages of such a structure are a low conduction band offset (0.04-0.06 eV), a high heavy-hole band offset (0.20-0.24 eV), and a relatively large well thickness (110-120 Angstrom). We propose a new method of overcoming these disadvantages by placing a tensile strain on both the well and the barrier and compensating for them with a compressive strained intrinsic layer.