Optical communication system having tunable sources

Abstract

An optical communication system with tunable sources may include a first optical source configured to supply a first optical signal having a first wavelength and a second optical source configured to supply a second optical signal having a second wavelength. An arrayed waveguide grating may include input waveguides having associated first and second passbands, the first passband being spectrally spaced from the second passband, the first passband including the first wavelength and the second passband including the second wavelength. A control circuit may selectively control the first and second optical sources to supply one of the first and second optical signals to one of the input waveguides, wherein, when the first optical signal is supplied to one of the plurality of input waveguides, the first optical signal is output from the output waveguide, and when the second optical signal is supplied to one of the plurality of input waveguides, the second optical signal is output from the output waveguide.

What is claimed is: 
     
         1 . An apparatus, comprising:
 a first optical source configured to supply a first optical signal having a first wavelength at a first temperature and a second optical signal having a second wavelength at a second temperature;   a second optical source configured to supply a third optical signal having a third wavelength at the first temperature and a fourth optical signal having a fourth wavelength at the second temperature;   an arrayed waveguide grating including a plurality of input waveguides, a first dielectric slab, a second dielectric slab, a plurality of intermediate waveguides extending between the first and second dielectric slabs, and an output waveguide, one of the plurality of input waveguides having associated first and second passbands at the first temperature, the first passband is spectrally spaced from the second passband, the first passband including the first wavelength and the second passband including the second wavelength, and said one of the plurality of input waveguides having associated third and fourth passbands at the second temperature, the third passband including the third wavelength and the fourth passband including the fourth wavelength; and   a control circuit configured to selectively control the first and second optical sources to supply one of the first optical signal or the second optical signal to said one of the plurality of input waveguides at the first temperature and one of the third or fourth optical signals at the second temperature, wherein, when the first optical signal is supplied to said one of the plurality of input waveguides, the first optical signal is output from the output waveguide, when the second optical signal is supplied to said one of the plurality of input waveguides, the second optical signal is output from the output waveguide, when the third optical signal is supplied to said one of the plurality of input waveguides, the third optical signal is output from the output waveguide, and, when the fourth optical signal is supplied to said one of the plurality of input waveguides, the fourth optical signal is output from the output waveguide.   
     
     
         2 . An apparatus in accordance with  claim 1 , further including:
 a substrate, the arrayed waveguide grating and the first and second optical sources being provided on the substrate;   a first heater; and   a second heater;   wherein the first and second heaters are configured to heat the first optical source to the second temperature.   
     
     
         3 . The apparatus in accordance with  claim 2 , wherein the first heater includes a carrier on a chip (COC). 
     
     
         4 . The apparatus in accordance with  claim 2 , wherein the first heater includes a thin film heater. 
     
     
         5 . The apparatus in accordance with  claim 2 , wherein the substrate includes indium phosphide (InP). 
     
     
         6 . The apparatus in accordance with  claim 1 , wherein the first and second passbands are separated by an free spectral range associated with the arrayed waveguide grating. 
     
     
         7 . The apparatus in accordance with  claim 6 , wherein the FSR is substantially equal 500 GHz. 
     
     
         8 . The apparatus in accordance with  claim 1 , wherein the first wavelength has an associated first frequency, the second wavelength has an associated second frequency, the third wavelength has an associated third frequency, and the fourth wavelength has an associated fourth frequency, the first and third frequencies being spectrally spaced from one another by 250 GHz, and the second and fourth frequencies being separated from one another by 250 GHz. 
     
     
         9 . The apparatus in accordance with  claim 1 , wherein said one of the plurality of input waveguides is a first one of the plurality of input waveguides, the apparatus further including fourth and fifth optical sources, the fourth optical source being configured to supply a fifth optical signal having a fifth wavelength, and the fifth optical signal having a sixth wavelength,
 wherein the control circuit controls the fourth and fifth optical sources to selective supply one of the fifth and sixth optical signals to a second one of the plurality of input waveguides.   
     
     
         10 . The apparatus in accordance with  claim 1 , wherein the first and second optical sources include first and second lasers, respectively, that output signals to first and second Mach-Zehnder interferometers, respectively. 
     
     
         11 . An apparatus, comprising:
 a first optical source configured to supply a first optical signal having a first wavelength;   a second optical source configured to supply a second optical signal having a second wavelength;   a third optical source configured to supply a third optical signal having a third wavelength;   a fourth optical source configured to supply a fourth optical signal having a fourth wavelength;   an arrayed waveguide grating having a plurality of input waveguides, a plurality of intermediate waveguides, and an output waveguide, one of the plurality of input waveguides having associated first, second, third, and fourth passbands, the first passband including the first wavelength, the second passband including the second wavelength, the third passband including the third wavelength, and the fourth passband including the fourth wavelength;   a control circuit configured to selectively control the first, second, third and fourth optical sources to supply one of the first, second, third, or fourth optical signals to said one of the plurality of input waveguides,   wherein, when the first optical signal is supplied to said one of the plurality of input waveguides, the first optical signal is output from the output waveguide, when the second optical signal is supplied to said one of the plurality of input waveguides, the second optical signal is output from the output waveguide, when the third optical signal is supplied to said one of the plurality of input waveguides, the third optical signal is output from the output waveguide, and, when the fourth optical signal is supplied to said one of the plurality of input waveguides, the fourth optical signal is output from the output waveguide.   
     
     
         12 . An apparatus in accordance with  claim 11 , wherein the first passband is spectrally spaced from the second passband by a free spectral range (FSR) of the arrayed waveguide grating, the second passband is spectrally spaced from the third passband by the FSR, and the third passband is spectrally spaced from the fourth passband by the FSR.