In this research, the effect of laser phase noise fixing is investigated for different optical channel parameters such as dispersion, attenuation and link distance for Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) systems. The effect of laser phase noise is examined at different data rates and link distances utilizing only one RF and optical carrier. In this research Phase Shift Keying (PSK) is used as a digital modulation format to maintain the maximum data rate with the acceptable BER value. By fixing the laser phase noise 1.7 Tb/s (111*16 Gb/s) can be obtained from 191.4 to 185.9 THz at 50 GHz spacing over 1000 km link distance using only one optical cable in C and L bands according to the Telecommunication Standardization Sector (ITU-T). In that case high level modulation formats (N-PSK) should be performed with DWDM technique.