A novel proposal of all-optical analog-to-digital conversion with unbalanced MZM and filter array

A novel phase-shifted optical analog-to-digital conversion proposal is presented and analyzed. Using an unbalanced MZM and specifically designed filter array, the desired phase shift between adjacent quantization channels can be realized. Comparing with existing schemes, the main advantage of this scheme is only one EOM and two wavelengths needed, regardless of the quantization resolution. Utilizing commercial products, analysis indicated that the number of bits as high as 8-bit and sampling rate up to 40 GS/s can be realized.