Techniques that provide cost effective optical fiber communication links for HDCP transmission systems and the like are provided. A single fiber for bidirectional communication is enabled, without wavelength selective unit to achieve the HDCP transmission. One embodiment of the present invention has a forward channel using a light source (e.g., VCSEL at about 850 nm) in the GHz modulation level (e.g., 1 GHz or greater), and a corresponding photodetector. The backward channel has a light source (e.g., LED at 630 nm) in the MHz modulation level (e.g., 10 MHz or less), and a corresponding photodetector. One application is for realizing a home entertainment system (e.g., DVD player and high definition television) that employs an HDCP-enabled communication link to transmit copy restricted digital content.