Single-transverse-mode laser diode with multi-mode waveguide region and manufacturing method of the same

Abstract

A laser diode of the present invention comprises a light waveguide. The light waveguide includes a multi-mode waveguide region.

What is claimed is:  
     
         1 . A laser diode which outputs single-transverse-mode light comprising a light waveguide including a multi-mode waveguide region.  
     
     
         2 . The laser diode according to  claim 1 , wherein said multi-mode waveguide region is a 1×1-multi-mode interference light waveguide.  
     
     
         3 . The laser diode according to  claim 1 , wherein said light waveguide comprises said multi-mode waveguide region and a pair of single-transverse-mode waveguide regions connected to both end portions of said multi-mode waveguide region.  
     
     
         4 . The laser diode according to  claim 2 , wherein said light waveguide comprises said multi-mode waveguide region and a pair of single-transverse-mode waveguide regions connected to both end portions of said multi-mode waveguide region.  
     
     
         5 . The laser diode according to  claim 3 , wherein said multi-mode waveguide region is wider than said single-transverse-mode waveguide region.  
     
     
         6 . The laser diode according to  claim 4 , wherein said multi-mode waveguide region is wider than said single-transverse-mode waveguide region.  
     
     
         7 . A manufacturing method of a laser diode which outputs a single-transverse-mode light comprising the step of forming a light waveguide including a multi-mode waveguide region.  
     
     
         8 . The manufacturing method of a laser diode according to  claim 7 , wherein said multi-mode waveguide region is a 1×1-multi-mode interference light waveguide.  
     
     
         9 . The manufacturing method of a laser diode according to  claim 7 , wherein said step of forming said light waveguide comprises the step of forming said multi-mode waveguide region and a pair of single-transverse-mode waveguide regions connected to both end portions of said multi-mode waveguide region.  
     
     
         10 . The manufacturing method of a laser diode according to  claim 8 , wherein said step of forming said light waveguide comprises the step of forming said multi-mode waveguide region and a pair of single-transverse-mode waveguide regions connected to both end portions of said multi-mode waveguide region.  
     
     
         11 . The manufacturing method of a laser diode according to  claim 9 , wherein said step of forming said multi-mode waveguide region comprises the step of making said multi-mode waveguide region wider than said single-transverse-mode waveguide region.  
     
     
         12 . The manufacturing method of a laser diode according to  claim 10 , wherein said step of forming said multi-mode waveguide region comprises the step of making said multi-mode waveguide region wider than said single-transverse-mode waveguide region.  
     
     
         13 . The manufacturing method of a laser diode according to  claim 8 , wherein said step of forming said multi-mode waveguide region comprises the steps of setting a desirable width W 1  of said multi-mode waveguide region, obtaining a length L of said multi-mode waveguide region corresponding to the width W 1  by using a multi-mode interference theory, and forming said multi-mode waveguide region having the length L and the width  
     
     
         14 . The manufacturing method of a laser diode according to  claim 10 , wherein said step of forming said multi-mode waveguide region comprises the steps of setting a desirable width W 1  of said multi-mode waveguide region, obtaining a length L of said multi-mode waveguide region corresponding to the width W 1  by using a multi-mode interference theory, and forming said multi-mode waveguide region having the length L and the width W 1 .  
     
     
         15 . The manufacturing method of a laser diode according to  claim 12 , wherein said step of forming said multi-mode waveguide region comprises the steps of setting a desirable width W 1  of said multi-mode waveguide region, obtaining a length L of said multi-mode waveguide region corresponding to the width W 1  by using a multi-mode interference theory, and forming said multi-mode waveguide region having the length L and the width W 1 .