High power distributed feedback ridge waveguide laser

Abstract

A distributed feedback ridge waveguide semiconductor laser diode having a waveguide region with a typical thickness of at least 500 nanometers and an effective refractive index difference between the ridge structure and exposed portions of the waveguide region which surround the ridge structure of less than 0.001. This permits the width of the ridge to be expanded beyond 3.5 microns thus translating directly to higher power outputs at 1.55 μm wavelengths, where carrier diffusion and carrier heating limit current density injected into the active region.

1 . A semiconductor laser diode comprising: 
 a body of a semiconductor material having a length of at least 2.5 millimeters; a waveguide region formed in the body, the waveguide region including active region for generating an optical mode of photons, the waveguide region having a thickness which supports a mode exhibiting a 5% or less overlap with a highly doped p-clad layer;    a ridge structure disposed over a side of the waveguide region; and    wherein the effective refractive index difference between the ridge structure and exposed portions of the waveguide region which surround the ridge structure is less than 0.002.    
     
     
         2 .- 24 . (Cancelled)