We introduce the concept of synchronous smart-pixel optical receivers,
and present the first use of a clocked-sense amplifier as a smart-pix
el optical receiver, Such a receiver uses the controlled application o
f positive feedback to obtain low-power compact digital amplification,
We describe the design and simulation of two types of optical receive
rs based on a clamped bit-line sense amplifier (CBLSA), and a conventi
onal sense amplifier (CSA), Both of these circuits have been realized
in 0.8 micron-linewidth foundry CMOS with hybrid-bonded GaAs-AlGaAs MQ
W detectors and modulators attached to the circuit, Operation in exces
s of 750 Mb/s is demonstrated, within a layout area of 44 mu m x 22 mu
m, with a bias-dependent estimated power dissipation of 1 to 2 mW, Op
eration with one or two input beams is possible, with approximate mini
mum detected photocurrent levels at 320 Mb/s of 8 mu A (similar to 100
fJ) for single-beam operation and 2.5 mu A/beam (similar to 30 fJ/bea
m) for two-beam operation, all in the CBLSA-based circuit.