It is fabricated that polarization insensitive gain medium for InGaAsP optical amplifiers. The active layer is a structure with alternating tensile and compressive strain quantum wells. The waveguide is made a taper with angled facets. In the experiment it is found that the structure can suppress the lasing and decrease the polarization sensitivity. The imbalance between TE and TM gains is less than 0.5 dB at bias current 125 mA, and 0.1 dB at 100 mA. FWHM is 40 nm within large current.