Abstract

A gain-flattened multiwavelength modelocked semiconductor laser generates 750 Mb/s return-to-zero pulses into 168 discrete wavelength channels. Optical time division multiplexing multiplies the pulse-repetition rate to 6 Gb/s per channel to yield an aggregate pulse rate of 1 Tb/s. Optical fiber deployment in the access network, which bridges the transport network and subscribers, hinges on the availability of cost-effective wavelength division multiplexing (WDM) light sources. Multiwavelength lasers have evolved into realistic candidates to satiate this need owing to their ability to generate a large number of WDM channels from a single source. Several groups have recently shown broadband multi-wavelength laser operation with high channel counts.^1–3 While cost sharing is inherent in the multiwavelength laser concept, the cost and complexity of a multiwavelength transmitter must not be so great as to negate the advantages of using a single multiwavelength source. The modelocked semiconductor diode laser is low-cost, broadband, compact, and it does not require extraordinary effort to operate in the multiwavelength regime. In contrast, other proposed multiwavelength sources typically involve femtosecond pulse generation, the use of nonlinear effects in fibers, low-temperature controlled environments, or an array of individual lasers.^1,4–6

© 2003 Optical Society of America