Patent ID: 7535033

Claim:
An array device comprising: a common n-type ohmic contact; an n-type substrate etched out from the backside so as to avoid absorption of incident light from the backside into said substrate, and said substrate connected to the part of said n-type ohmic contact; at least one n-type buffer layer attached to said n-type substrate; at least one InGaAs absorption layer connected to said buffer layers, with an array of sections etched into said absorption layer so as to electrically isolate each said section; a spacer layer attached to each said section of said absorption layer so as to protect said absorption layer from diffused dopants; at least one doped p-type In-based ohmic contact layers covering each isolated section of the absorption layer, wherein said p-type In-based ohmic contact layers comprise InAs 0.6 P 0.4 and/or highly-doped InP; and a plurality of p-type ohmic contacts, one on each said section of the absorption layer, connected to said p-type In-based ohmic contact layer, wherein each said p-type ohmic-contact to each section of said absorption layer forms an individual device and wherein the array device is illuminated from the backside of the substrate.