Heterodyne based optical spectrum analysis with reduced data acquisition requirement

A method for optical spectrum analysis that utilizes optical heterodyne detection, the method comprising:

• providing an input signal;
• providing a swept local oscillator signal that sweeps across a range of frequencies;
• combining said input signal with said swept local oscillator signal to create a combined optical signal;
• detecting said combined optical signal to generate a heterodyne beat signal;
• stretching said heterodyne beat signal;
• obtaining heterodyne beat signal data from said stretched heterodyne beat signal;
• and
• generating, from said heterodyne beat signal data, an output signal that is indicative of an optical parameter of said input signal.

A system for optical spectrum analysis comprising:

• a local oscillator source for generating a swept local oscillator signal that sweeps across a range of frequencies;
• an optical coupler having a first input and a second input, said first input being optically connected to receive an input signal, said second input being optically connected to said local oscillator source to receive said swept local oscillator signal, said optical coupler having an output for outputting a combined optical signal that includes said input signal and said swept local oscillator signal;
• a heterodyne receiver having an input for receiving said combined optical signal from said optical coupler, a low resolution data acquisition unit for outputting low resolution heterodyne beat signal data that is representative of said combined optical signal, and a high resolution data acquisition unit for outputting high resolution heterodyne beat signal data that is representative of said combined optical signal;
• and
• a processor for utilizing said low resolution heterodyne beat signal data from said heterodyne receiver to generate a low resolution output signal that is indicative of an optical parameter of said input signal and for utilizing said high resolution heterodyne beat signal data from said heterodyne receiver to generate a high resolution output signal that is indicative of an optical parameter of said input signal.

A method for optical spectrum analysis that utilizes optical heterodyne detection, the method comprising:

• providing an input signal;
• providing a swept local oscillator signal that sweeps across a range of frequencies;
• combining said input signal with said swept local oscillator signal to create a combined optical signal;
• detecting said combined optical signal to generate a heterodyne beat signal;
• obtaining low resolution heterodyne beat signal data from said heterodyne beat signal;
• obtaining high resolution heterodyne beat signal data from said heterodyne beat signal;
• generating, from said low resolution heterodyne beat signal data, a low resolution output signal that is indicative of an optical parameter of said input signal;
• and
• generating, from said high resolution heterodyne beat signal data, a high resolution output signal that is indicative of an optical parameter of said input signal.

A method for optical spectrum analysis that utilizes optical heterodyne detection, the method comprising:

• providing an input signal;
• providing a swept local oscillator signal that sweeps across a range of frequencies;
• combining said input signal with said swept local oscillator signal to create a combined optical signal;
• detecting said combined optical signal to generate a heterodyne beat signal;
• obtaining low resolution heterodyne beat signal data from said heterodyne beat signal;
• generating, from said low resolution heterodyne beat signal data, a low resolution output signal that is indicative of an optical parameter of said input signal;
• obtaining high resolution heterodyne beat signal data from said heterodyne beat signal in response to said low resolution output signal that is indicative of an optical parameter of said input signal;
• and
• generating, from said high resolution heterodyne beat signal data, a high resolution output signal that is indicative of an optical parameter of said input signal.