Resolution upgrade toward 6-bit optical quantization using power-to-wavelength conversion for photonic analog-to-digital conversion

We demonstrate a resolution upgrade toward 6 bit optical quantization using a power-to-wavelength conversion without an increment of system parallelism. Expansion of a full-scale input range is employed in conjunction with reduction of a quantization step size with keeping a sampling-rate transparency characteristic over several 100  sGS/s. The effective number of bits is estimated to 5.74 bit, and the integral nonlinearity error and differential nonlinearity error are estimated to less than 1 least significant bit.