Design challenges and performance optimization of an all-optical analog-to-digital converter (AOADC) is presented here. The paper addresses both microwave and optical design of a leaky waveguide optical deflector based on electro-optic (E-O) polymer. The designed E-O deflector should allow an AOADC operating over 44 giga-samples-per-seconds (GSPS) with an estimated effective resolution of 6.5 bits and power consumption of only 4W. In addition, for ease of access from both optical and RF perspective, via-holes less broad bandwidth transition from grounded coplanar line to coupled microstrip line (GCPW-CMS) is designed and realized. Measurement results for the back-to-back configuration of this transition are reported with a bandwidth of over 35 GHz.