4-λ Laser Array Multi-Chip Transmitter Module using Conical-Microlensed Fibers

Traditionally, increasing the transmission bandwidth in telecommunication systems has been accomplished using time-division-multiplexing. This is because the cost of transmission per bit per km of fiber has been decreasing continuously in the last fifteen years. In the case of bit rates above 2.5 Gb/s, fiber dispersion can quickly set a limit on the transmission distance. Another approach to increase the capacity is to exploit the fiber bandwidth by using wavelength division multiplexing (WDM)[1]. This paper describes a 4-λ, laser array transmitter module prototype that operates at wavelengths of 1546, 1550, 1554, and 1558nm and at a bit rate of 155 Mb/s.