Bit-Interleaved Optical Bus for High-Speed Secure Multi-Board System

摘要

Optical backplane bus based on glass substrate with volume holographic gratings on top surface possesses a great ability to broadcast information. This feature is utilized to accomplish a bit-interleaved optical interconnect system. In this system, each daughter board sends only one bit per round and the bit pulses from different boards can cascade in a designed series when the transmitters are distributed in an appropriate manner. In this way, even slow electronic chips can be coordinated to generate an aggregate bandwidth up to 10Gbps, which is impossible to achieve with a multi-drop electrical bus. Besides the benefits of high data rate and low crosstalk, such a bit-interleaved architecture provides a secure data storage method. Each daughter board only stores a quarter bits of any byte, so that no single board has the entire information and security is enhanced. Alignment tolerance and power budget of the proposed optical interconnect system is theoretically calculated and experimentally verified. With collimating lenses, the packing density of transceivers is more than 4/cm~2, and thus the signal density can be above 40Gbps/cm~2/board. The insertion loss due to misalignment and beam divergence is measured to be approximately 3dB. The bit error rate (BER) of 10Gbps receivers with -12dBm sensitivity is estimated to be below 10~(-12).