the present invention relates to an optical access system for dual service network , which mainly comprises an optical modulation device which is used to receive on - off keying signal from cable network and radio frequency signal from wireless network , the optical modulation device then modulates the ook signal and the rf signal to an optical signal and send out an output optical signal . lastly , the output optical signal is being delivered to an optical receiving device through an optical fiber transmission channel , and the optical receiving device can access the ook signal and rf signal from the output optical signal . in addition , the present invention does not require remote nodes to use any optical filter to discern on - off keying signal from cable network and rf signal from wireless network . the present invention can also apply to the field of wavelength - division multiplexing system .