Abstract: An optical multi-channel data communication link transmits data from a transmitter to a remote receiver. The link includes a multimode laser diode source connected to the transmitter, a device for modulating the source with each channel of data to generate a modulated light wave, and a wavelength division multiplexing device at the transmitter. The wavelength division multiplexing device has paraxial optics for multiplexing the light waves to produce a multiplexed signal. Multimode fiber optic means are connected to the multiplexer and pass the multiplexed signal to the remote receiver. A wavelength division multiplexer has paraxial optics for demultiplexing the multiplexed signals at the receiver to produce demultiplexed light waves. Each of the demultiplexed light waves are converted for use by the receiver.