US 11,757,252 B2
Oxide aperture shaping in vertical cavity surface-emitting laser
Mirko Hoser, Zurich (CH); Abram Jakubowicz, Pfaeffikon (CH); and Tomi Leinonen, Zurich (CH)
Assigned to II-VI Delaware, Inc., Wilmington, DE (US)
Filed by II-VI Delaware, Inc., Wilmington, DE (US)
Filed on Mar. 1, 2022, as Appl. No. 17/683,947.
Application 17/683,947 is a division of application No. 16/406,140, filed on May 8, 2019, granted, now 11,289,881.
Prior Publication US 2022/0190558 A1, Jun. 16, 2022
Int. Cl. H01S 5/183 (2006.01); H01S 5/30 (2006.01); H01S 5/20 (2006.01)
CPC H01S 5/18327 (2013.01) [H01S 5/1835 (2013.01); H01S 5/18311 (2013.01); H01S 5/18313 (2013.01); H01S 5/18347 (2013.01); H01S 5/18361 (2013.01); H01S 5/2081 (2013.01); H01S 5/3013 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A vertical cavity surface emitting laser (VCSEL) comprising:
a substrate having a top major surface;
a first distributed Bragg reflector (DBR) formed on the top major surface of the substrate, the first distributed Bragg reflector comprising a stack of layers of alternating refractive index value;
a second DBR disposed over the first DBR and comprising a stack of layers of alternating refractive index, the second DBR exhibiting an elliptical mesa structure of a predetermined cross-section geometry required to create an oxide aperture of a circular shape; and
an active layer disposed between the first DBR and the second DBR, wherein a layer within the second DBR has an larger concentration of a quickly oxidizing material than the remaining layers of the second DBR and is defined as an aperture layer that exhibits anisotropic oxidation, the aperture layer including an outer insulating boundary region coincident with sidewalls of the elliptical mesa structure and an inner oxide aperture of a circular shape, the circular shape defined by anisotropic oxidation of the aperture layer.