Since high data rates are necessary for optical communication systems, M-ary amplitude shift keying (ASK) has been developed to improve spectral efficiency. The spectral efficiency is measured in terms of bits per second per Hertz (bps/Hz) and is determined by the bandwidth. Thus, M-ary ASK allows higher data rate transmissions at lower bandwidth to carry multiple data bits in a single symbol. In this project, MCML logic is utilized to implement a M-ary ASK transmitter, which consists of an encoder, a D-Flip flop, a signal generator, and a laser driver. The differential topology is employed in all circuits to stabilize the current ripple in the power supply and to operate in high-speed.