In this paper, a power saving optical receiver (Rx) module has been designed, fabricated using a 0.13-mu m CMOS technology and demonstrated the performance with experimental results. In the Rx module, a power control block is designed to control the power of Rx according to the presence or absence of an incoming signal at the input of Rx. The Rx switches to a passive operation mode when there is no signal at Rx input. In the passive operation mode, the fabricated Rx shows a power saving efficiency of about 51%, where Rx is not receiving. When there is an input signal at Rx input, the Rx switches to an active operation mode with a system efficiency of about 97.5%. The experimental data shows that the Rx module consumes of about 67 mW at 1.3 V and power control block consumes of about 1.6 mW at 1.4 V. The measured 3-dB bandwidth of 2.56 GHz was recorded for optical Rx module. The bit error rate (BER) performance of 10(-12) is achieved for the proposed optical Rx module up to 2.5 Gbps data rate with a clear eye-diagram by a very low optical input power of about -3 dBm.