Photodetector with integrated temperature control element

Abstract

A temperature-controlled photodetector sub-system is described. The temperature control element allows the operation of the photodetector at a desired temperature. The temperature control element can be a heater or a cooler. In some cases, the photodetector is a germanium photodetector. In some cases a temperature measuring device is provided. In some cases, a control circuit is used to control the temperature of the germanium photodetector within a temperature range, or at a temperature of interest. An advantage provided by the apparatus described is the operation of the photodetector so that the responsivity of the germanium detector can be held at essentially a constant value.

1 - 28 . (canceled) 
     
     
         29 . A photonic device comprising:
 a wafer comprising a waveguiding layer;   a photodetector integrated with the wafer in optical communication with the waveguiding layer; and   a temperature control element integrated with the wafer proximate to the photodetector so as to control the temperature thereof.   
     
     
         30 . The photonic device of  claim 29 , wherein the photodetector is a germanium photodetector. 
     
     
         31 . The photonic device of  claim 29 , wherein the temperature control element comprises one of a heater and a cooler. 
     
     
         32 . The photonic device of  claim 29 , wherein the temperature control element is disposed at most 10 microns apart from the photodetector. 
     
     
         33 . The photonic device of  claim 29 , wherein the temperature control element is disposed less than 50 microns apart from the photodetector. 
     
     
         34 . The photonic device of  claim 29 , wherein the temperature control comprises a Peltier device. 
     
     
         35 . The photonic device of  claim 29 , further comprising a thermal measurement device situated proximate to the photodetector. 
     
     
         36 . The photonic device of  claim 35 , including a control circuit connecting the temperature control element with the thermal measurement device and configured to control a temperature of the photodetector in a predetermined temperature range. 
     
     
         37 . The photonic device of  claim 29 , wherein the temperature control element comprises two heaters disposed on opposite sides of the photodetector or two coolers disposed on opposite sides of the photodetector. 
     
     
         38 . The photonic device of  claim 29 , wherein the waveguiding layer comprises a semiconductor. 
     
     
         39 . The photonic device of  claim 29 , wherein the temperature control element comprises a resistive heater. 
     
     
         40 . The photonic device of  claim 29  further comprising an electrical signal barrier disposed between the photodetector and the temperature control element. 
     
     
         41 . The photonic device of  claim 40 , wherein the electrical signal barrier comprises a p-n-p-n junction. 
     
     
         42 . A method of operating a photonic device in a predefined wavelength range across a first temperature range, the photonic device comprising a wafer and a photodetector integrated therewith, the photodetector being capable of efficiently detecting light of the predefined wavelength range within only a portion of the first temperature range, the method comprising:
 integrating a temperature control element with the wafer proximate to the photodetector, and   operating the temperature control element to maintain a temperature of the photodetector within the pre-determined portion of the first temperature range.   
     
     
         43 . The method of  claim 42 , comprising using a germanium photodetector as the photodetector. 
     
     
         44 . The method of  claim 42 , comprising using one of a heater and a cooler as the temperature control element. 
     
     
         45 . The method of  claim 42 , comprising integrating the temperature control element at most  10  microns away from the photodetector. 
     
     
         46 . The method  claim 42 , wherein the photodetector is disposed on a semiconductor layer, and wherein the integrating the temperature control element comprises forming the temperature control element at least in part in the semiconductor layer or over the semiconductor layer. 
     
     
         47 . The method  claim 46 , comprises forming an electrical signal barrier in the semiconductor layer between the temperature control element and the photodetector. 
     
     
         48 . The method of  claim 42 , wherein integrating the temperature control element comprises integrating a heater proximate to the photodetector.