Integrated optical phased array

Abstract

An integrated optical phased array includes an input channel receiving an optical input signal, and a multitude of signal processing channels each adapted to supply an associated optical output signal along a first axis in response to the input signal. Each signal processing channel includes, in part, a phase modulator adapted to modulate the phase of the signal travelling through the channel, thereby to control or steer the output signal of the phased array. Each channel optionally includes first and second photo detection circuits respectively generating first and second detection signals. The first and second detection signals in each channel may be used to modulate the amplitude and/or phase of the output signal of that channel thereby to control and steer the output signal of the phased array.

What is claimed is: 
     
         1 . An integrated optical phased array comprising:
 an input channel adapted to receive an optical input signal; and   a first plurality of signal processing channels each adapted to supply an associated optical output signal in response to the input signal along a first axis, each signal processing channel comprising:
 a first photo detection circuit adapted to generate a first detection signal in response to a first optical signal travelling through a first optical path in the channel; 
 a second photo detection circuit adapted to generate a second detection signal in response to a second optical signal travelling through a second optical path in the channel; 
 a first signal modulation block adapted to modulate an amplitude of a third optical signal travelling a third optical path in the channel in response to the first detection signal; and 
 a phase modulation block adapted to modulate a phase of a fourth optical signal travelling a fourth optical path in the channel in response to the second detection signal, wherein said second optical signal is defined by splitting and routing the input signal. 
   
     
     
         2 . The integrated optical phase array of  claim 1  wherein said first signal modulation block of at least one channel is adapted to modulate an amplitude of the channel's associated third optical signal by varying a phase of the channel's associated third optical signal. 
     
     
         3 . The integrated optical phase array of  claim 1  wherein said first and fourth optical signals of at least one channel are generated from a fifth optical signal travelling through the at least one channel. 
     
     
         4 . The integrated optical phase array of  claim 1  wherein each channel further comprises:
 a first control circuit adapted to receive the channel's associated first detection signal and apply a first control signal to the channel's associated amplitude modulation block to modulate the amplitude of the channel's associated third optical signal. 
 
     
     
         5 . The integrated optical phase array of  claim 4  wherein each channel further comprises:
 a second control circuit adapted to receive the channel's associated second detection signal and apply a second control signal to the channel's associated phase modulation block to modulate the phase of the channel's associated fourth optical signal. 
 
     
     
         6 . The integrated optical phase array of  claim 1  wherein said first optical signal of at least one channel is generated from the channel's associated third optical signal. 
     
     
         7 . The integrated optical phase array of  claim 6  wherein said first and fourth optical signals of at least one channel have substantially similar phases and different amplitudes. 
     
     
         8 . The integrated optical phase array of  claim 7  wherein said second optical signal of at least one channel is further defined by an output signal of the channel's associated phase modulation block. 
     
     
         9 . The integrated optical phase array of  claim 1  wherein said first optical signal of at least one channel is generated from the channel's associated third and fourth optical signals. 
     
     
         10 . The integrated optical phase array of  claim 9  wherein said third and fourth optical signals of at least one channel have substantially similar phases. 
     
     
         11 . The integrated optical phase array of  claim 10  wherein said third and fourth optical signals of at least one channel are generated by splitting a fifth signal travelling through the at least one channel. 
     
     
         12 . The integrated optical phase array of  claim 1  wherein said first photo detection circuit of at least one channel is a photo diode. 
     
     
         13 . The integrated optical phase array of  claim 12  wherein said second photo detection circuit of at least one channel is a photo diode. 
     
     
         14 . The integrated optical phase array of  claim 1  further comprising:
 a second plurality of signal processing channels positioned above the first plurality of signal processing channels. 
 
     
     
         15 . The integrated optical phase array of  claim 14  further comprising:
 a third plurality of signal processing channels positioned below the first plurality of signal processing channels. 
 
     
     
         16 . A method of steering an optical signal by varying relative phases of a plurality of output signals generated by a first plurality of optical signal processing channels, the method comprising:
 delivering an optical input signal to an input channel;   generating a first detection signal in response to a first optical signal travelling through a first optical path of each of the first plurality of signal processing channels;   generating a second detection signal in response to a second optical signal travelling through a second optical path of each of the first plurality of signal processing channels;   modulating an amplitude of a third optical signal travelling through a third optical path of each of the first plurality of signal processing channels in response to an associated first detection signal;   modulating a phase of a fourth optical signal travelling through a fourth optical path of each of the first plurality of signal processing channels in response to an associated second detection signal; and   generating the second optical signal by splitting and routing the optical input signal.   
     
     
         17 . The method of  claim 16  further comprising:
 modulating an amplitude of the third optical signal by varying a phase of the third optical signal. 
 
     
     
         18 . The method of  claim 16  further comprising:
 splitting a fifth signal to generate the first and fourth optical signals. 
 
     
     
         19 . The method of  claim 16  further comprising:
 generating a first control signal in response to the first detection signal; and 
 modulating the amplitude of the third optical signal in response to the first control signal. 
 
     
     
         20 . The method of  claim 16  further comprising:
 generating a second control signal in response to the second detection signal; and 
 modulating the phase of the fourth optical signal in response to the second control signal. 
 
     
     
         21 . The method of  claim 16  further comprising:
 generating the first optical signal from the third optical signal. 
 
     
     
         22 . The method of  claim 21  further comprising:
 maintaining the first and fourth optical signals substantially in phase. 
 
     
     
         23 . The method of  claim 22  further comprising:
 generating the second optical signal in accordance with the phase modulated fourth optical signal. 
 
     
     
         24 . The method of  claim 16  further comprising:
 coupling the third and fourth optical signals to generate the first optical signal. 
 
     
     
         25 . The method of  claim 24  further comprising:
 maintaining the third and fourth optical signals substantially in phase. 
 
     
     
         26 . The method of  claim 25  further comprising:
 splitting a fifth optical signal to generate the third and fourth optical signals. 
 
     
     
         27 . The method of  claim 16  further comprising:
 generating the first detection signal using a first photo diode. 
 
     
     
         28 . The method of  claim 27  further comprising:
 generating the second detection signal using a second photo diode. 
 
     
     
         29 . The method of  claim 16  further comprising:
 forming a second plurality of signal processing channels above the first plurality of signal processing channels. 
 
     
     
         30 . The method of  claim 29  further comprising:
 forming a third plurality of signal processing channels below the first plurality of signal processing channels. 
 
     
     
         31 . An integrated optical phased array comprising:
 an input channel adapted to receive an optical input signal; and   a plurality of signal processing channels each adapted to supply an associated optical output signal in response to the input signal along a first axis, each signal processing channel comprising a phase modulation block adapted to modulate a phase of a signal travelling through the channel in response to a control signal received by the channel.   
     
     
         32 . A method of steering an output optical signal comprising:
 delivering an optical input signal to an input channel; and   modulating a phase of an optical signal travelling through each of a plurality of channels in response to a control signal received by the channel, the optical signal travelling through each channel being defined by the input signal, the output optical signal being defined by a plurality of phase modulated signals of the plurality of channels.