Abstract: The invention is an optical device and method of fabrication which mitigates the problem of Zn migration in the cladding and waveguide regions. The contact region includes carbon, which acts as a p-type dopant in ternary semiconductor material. The contact layer is made of InGaAs or InGaAsP, and the invention is most advantageously used in an electroabsorption modulated laser or capped mesa buried heterostructure laser.

Abstract: A method of producing a batch of MQW lasers from a plurality of wafers having doping concentrations within a concentration range. The MQW lasers are produced by epitaxially growing an InGaAsP quaternary layer on the substrates in a metal-organic chemical vapor deposition (MOCVD) reactor. The method includes the steps of segregating the substrates into groups based upon the substrate doping concentrations and batch producing the lasers at specific target wavelengths for each segregated substrate group.

Abstract: A method for altering a dopant front profile of a dopant in a wafer is disclosed. An initial wafer is provided with an upper doped layer and a lower undoped layer. An oxide layer is grown over a portion of the wafer while a second portion of the wafer remains oxide-free. The wafer is then exposed to a substantially non-growth enhancement diffusion environment that contains the dopant at a given flow rate, but lacks additional materials which would cause growth on the exposed portions of wafer. After a predetermined amount of diffusion is allowed to occur, the wafer is removed from the diffusion environment and the oxide layer is removed.