| Summary: | The technique of wavelength division multiplexing (WDM) is currently attracting considerable interest from the telecommunications and computer industries alike as a means both for increasing the transmission rates of existing fiber-optic links and for attaining enhanced flexibility in future optical networks. Studies of WDM systems have indicated the need for a single-output multi-wavelength laser source whose wavelengths can be controlled to within a small fraction of the inter-channel spacing. Furthermore, a monolithically integrated laser source realized by simple processing techniques would, due to robustness and reduced packaging costs, make WDM a more economically viable option. This thesis describes the design, fabrication and characteristics of a new type of monolithically integrated semiconductor laser, the multi-stripe array grating integrated cavity (MAGIC) laser, that gives simultaneous multiple wavelength laser emission from a single output port. Each emission wavelength may be independently selected from a comb of "allowed" operating wavelengths that are precisely set at the fabrication stage. The laser is best suited to wavelength spacings > 1nm and may be fabricated in different materials systems for operation in different wavelength ranges. This thesis is primarily concerned with fabrication in the InGaAsP/lnP materials system for operation in the 1.5mum communication band. A prototype version of the MAGIC laser has been fabricated; it emits 15 different wavelengths spaced at ~2nm intervals over a ~30nm range around 1.5mum. The spacing is constant to within 0.03nm, the highest as-fabricated wavelength linearity so far recorded for a monolithic multi-wavelength laser source. Absolute wavelength accuracy is ~2nm; exact coincidence with design values may be obtained by temperature tuning the laser mount (0.11nm/°C sensitivity).
|
|---|
