Ternary InGaAs bulk layer is used as active region. TM mode gain is enhanced by directly introducing 0.20% tensile strain into bulk InGaAs active layer so that a polarization insensitive semiconductor optical amplifier (SOA) for converter is fabricated. The desired tensile strain value is achieved by only changing the TMGa source flow during low-pressure metalorganic vapor-phase epitaxy (LP-MOVPE). At injection current of 200 mA, the fabricated SOA has a 3 dB optical bandwidth of 50 nm and the gain ripple is less than 0.5 dB. More important is that the polarization sensitivity of SOA is less than 1.1 dB over a wide current and wavelength range. Under bias of current of 200 mA, for λ=1.55 μm, the SOA shows less than 1 dB polarization sensitivity, 14 dB fiber to fiber gain, 3 dBm saturation output power and more than 30 dB chip gain. A high conversion efficiency can be obtained when SOA is used as wavelength converter. A better performance SOA will be achieved if the coupling loss between the SOA chip and the fiber is decreased further.