Abstract

It is well-known that electrical I/O bottlenecks in integrated circuits can be remedied with optical interconnects. An optical interconnect link requires a transmitter to convert intrachip electrical signals into optical signals suitable for fiber-optic interchip communication, and a receiver to reconvert optical signals at the fiber output into electrical signals on the chip. We consider an approach using an off-chip laser as an optical power supply, connected via optical fiber to an on-chip electrooptic modulator that imprints the distributed optical power with the desired information. Optical fiber carries the modulated optical signal to a receiver, which may be on a different chip or board. The signal-to-noise ratio (SNR) at the receiver output is 10logSNR = P-L(λ)+ 10log[αβ(ΔV,λ], where P is the laser output power in dBm, the optical loss L in the link is a function of wavelength λ, the parameter α is directly proportional to the detector responsivity and inversely proportional to the bit-rate and receiver noise-equivalent-power, and the modulation depth β is a function of λ as well as the voltage-swing ΔV applied to the on-chip modulator.

© 1991 Optical Society of America