50 Channel VSB-AM Video Transmission Employing a Linearized External Modulator

The 1320 nm diode-pumped Nd: YAG laser is an attractive source for AM video transmission due to the high output power ( > 200 mW) and low RIN ( < −170 dB/Hz) over the video bandwidth. When used in conjunction with a predistortion-linearized Mach-Zehnder modulator [1] a 13.5 dB optical power budget is obtained for 50 channel transmission with video Carrier-to-Noise Ratios (CNR) of 52 dB and composite distortion products (CSO and CTB) less than −60 dBc. The demonstrated power budget is sufficient to allow 4 way power splitting with the remaining margin comparable to the best results obtained with DFB laser based AM transmission systems.