SYSTEM AND METHOD FOR IMPROVED CHIRPED LIDAR

1 . A lidar comprising:

a first laser source configured to generate a first laser output at a first frequency;

a second laser source configured to generate a second laser output at a second frequency, wherein the first frequency is different from the second frequency;

a combining coupler configured to combine the first laser output and the second laser output into a combined output;

at least one fiber configured to output a first portion of the combined output as a transmit signal toward a target and to receive a reflected portion of the transmit signal reflected back from the target;

a mixing coupler configured to mix the received reflected portion of the transmit signal with a second portion of the combined output and output a mixed signal;

a wavelength filter configured to receive the mixed signal, to separate the mixed signal into a first separated mixed signal corresponding to the first frequency and a second separated mixed signal corresponding to the second frequency;

a first detector configured to detect the first separated mixed signal; and

a second detector configured to detect the second separated mixed signal.

2 . The lidar of claim 1 , further comprising:

a separator configured to:

receive the combined output,

output a transmit signal onto the at least one fiber, the transmit signal corresponding to a portion of the combined output,

receive a return signal from the at least one fiber, and

output the return signal as a received signal.

3 . The lidar of claim 1 , further comprising:

a delay configured to:

receive the second portion of the combined output, and

output a delayed version of the received second portion of the combined output to the mixing coupler.

4 . The lidar of claim 1 , wherein the wavelength filter comprises:

a first wavelength filter configured to separate and output the first mixed signal corresponding to the first frequency from the mixed signal and output a remaining portion of the mixed signal; and

a second wavelength filter configured to separate and output the second mixed signal corresponding to the second frequency from the remaining portion of the mixed signal.

5 . A lidar comprising:

a first laser source configured to generate a first laser output at a first frequency;

a second laser source configured to generate a second laser output at a second frequency, wherein the first frequency is different from the second frequency;

a combining coupler configured to combine the first laser output and the second laser output into a combined output;

an output multiplexer configured to split the combined output into five transmit signals, each of the five transmit signals having approximately a same power level;

a fiber for each of the five transmit signals configured to output a respective one of the five transmit signals toward a target and to receive a reflected portion of the respective one of the five transmit signals reflected back from the target;

a mixing coupler for each of the five transmit signals configured to mix each of the received reflected portion of the respective one of the five transmit signals with a second portion of the combined output and output a corresponding mixed signal for each of the five transmit signals;

a wavelength filter for each of the five transmit signals configured to separate each of the corresponding mixed signals into a first mixed signal corresponding to the first frequency and a second mixed signal corresponding to the second frequency;

a first detector for each of the five transmit signals configured to detect the first mixed signal; and

a second detector for each of the five transmit signals configured to detect the second mixed signal.

6 . A method comprising:

generating a first laser output at a first frequency from a first laser source;

generating a second laser output at a second frequency from a second laser source, wherein the first frequency is different from the second frequency;

combining the first laser output and the second laser output into a combined output;

transmitting a first portion of the combined output as a transmit signal toward a target;

receiving a reflected portion of the transmit signal reflected back from a point on the target;

mixing the received reflected portion of the transmit signal with a second portion of the combined output to produce a mixed signal;

separating, via a wavelength filter, the mixed signal into a first mixed signal corresponding to the first frequency and a second mixed signal corresponding to the second frequency;

detecting the first mixed signal via a first detector;

detecting the second mixed signal via a second detector; and

determining a range and a Doppler velocity for the point on the target from the detected first mixed signal and the detect second mixed signal.

7 . The lidar of claim 1 , wherein the wavelength filter is an optical wavelength filter.

8 . The lidar of claim 5 , wherein each of the wavelength filters is an optical wavelength filter.

9 . The method of claim 6 , wherein separating, via a wavelength filter, the mixed signal into a first mixed signal corresponding to the first frequency and a second mixed signal corresponding to the second frequency comprises separating, via an optical wavelength filter, the mixed signal into a first mixed signal corresponding to the first frequency and a second mixed signal corresponding to the second frequency.