A symmetrical digital photonic splitting switch with a low insertion loss and a low driving voltage is developed using carrier injection in a silicon-germanium material for optical communication systems and networks at a wavelength of 1.55 mum. The switch structure has been improved based on a traditional 1x2 Y-shaped configuration by using two widened carrier injection regions. The switch has a threshold voltage of 1.0 V and a corresponding threshold current of 85 mA on one of the two output waveguide arms. The calculated driving current density is 5.7 kA/cm2 and the calculated power consumption is 85 mW at the 85 mA of threshold current. The measured insertion loss and the crosstalk are 5.2 dB and -9.6 dB, respectively, at driving voltage over 2 V.