Vertical-cavity surface emitting laser diode

Abstract

The present invention provides a VCSEL (vertical-cavity surface emitting laser) diode, in which a p-type cladding layer is formed on an active layer and surrounded with an insulation edge. An annular p-type electrode is formed on the ptype cladding layer close to the insulation edge and an upper DBR mirror is formed therewithin. According to the present invention, light beams emitting from the active layer will not be shielded by a central electrode and brightness of the laser diode is improved.

1 . A VCSEL (vertical-cavity surface emitting laser) diode, comprising: 
 an n-type cladding layer with a top surface partially etched;    an active layer with quantum well structure formed on the un-etched surface of said n-type cladding layer;    a p-type cladding layer surrounded with an insulating edge and formed on said active layer;    an n-type ohmic contact electrode deposited on said etched surface of said n-type cladding layer;    an annular ptype ohmic contact electrode deposited on said p-type cladding layer close to said insulating edge;    an upper DBR pair of dielectric material formed on said p-type cladding layer at least within said annular p-type ohmic contact electrode;    a bottom DBR pair of dielectric material formed beneath said n-type cladding layer;    a metal conductive layer formed beneath said bottom DBR pair; and    a permanent substrate formed beneath said metal conductive layer.    
     
     
         2 . The VCSEL diode as claimed in  claim 1 , wherein said upper DBR pair is made from a composite material selected from the group consisting of ZnSe/MgF 2 , SiO 2 /Si, Si 3 N 4 /Si, TiO 2 /Si, Ta 2 O 5 /Si, HfO 2 /SiO 2 , Ta 2 O 5 /SiO 2 , ZrO 2 /SiO 2 , TiO 2 /SiO 2 .  
     
     
         3 . The VCSEL diode as claimed in  claim 1 , wherein said upper DBR pair is a metal reflective layer.  
     
     
         4 . The VCSEL diode as claimed in  claim 1 , wherein said bottom DBR pair is made from a composite material selected from the group consisting of ZnSe/MgF 2 , SiO 2 /Si, Si 3 N 4 /Si, TiO 2 /Si, Ta 2 O 5 /Si, HfO 2 /SiO 2 , Ta 2 O 5 /SiO 2 , ZrO 2 /SiO 2 , TiO 2 /SiO 2 .  
     
     
         5 . The VCSEL diode as claimed in  claim 1 , wherein said bottom DBR pair is a metal reflective layer.  
     
     
         6 . The VCSEL diode as claimed in  claim 1  further comprising a transparent conductive film formed on said p-type ohmic contact electrode.  
     
     
         7 . The VCSEL diode as claimed in  claim 1  further comprising an insulating spacer between said n-type cladding layer and said bottom DBR pair, and said insulating spacer is formed beneath said n-type cladding layer but not overlaps main area of said active layer, and said metal conductive layer and said permanent substrate are formed beneath said bottom DBR pair only corresponding to said insulating spacer.