Low-cost, enhanced performance DFB Lasers

A novel DFB laser structure, referred to as CSDFB, is presented that, different from conventional designs, simultaneously allows to obtain very high yield single mode behaviour even without applying facet coatings, high slope efficiency, and low beam divergence. These advantages result from the incorporation of a curved and tapered laser waveguide designed such that a constant period DFB grating can be utilized. Preliminary feedback measurements have indicated enhanced immunity to optical back-reflection in comparison to a conventional DFB structure. The CSDFB design has large potential of reducing transmitter costs due to both reduced chip and module fabrication costs.