Patent ID: 8748797

Claim:
A method for demultiplexing optical signals, the method comprising: a first photodiode accepting first optical signals in a first range of wavelengths with second optical signals in a second range of wavelengths greater than the first range; generating first electrical signals in the first photodiode in response to the optical signals in the first range; a second photodiode accepting the optical signals in the second range; providing the first photodiode overlying the second photodiode, where the first photodiode has a first coefficient of absorption associated with the first range of wavelengths and the second photodiode has a second coefficient of absorption and a half value layer (HVL) associated with the second range of wavelengths, and wherein the first photodiode has thickness less than the HVL of the second photodiode; and generating second electrical signals in the second photodiode in response to the second optical signals.