Systems and methods for pulsed-wave LIDAR
A system and method for pulsed-wave LIDAR to support the operation of a vehicle. In some implementations, the system and method include modulating an optical signal to generate a modulated optical signal; selecting a plurality of pulses from the modulated optical signal to generate a pulsed envelope signal; transmitting the pulsed envelope signal via one or more optical elements; receiving a reflected signal responsive to transmitting the pulsed envelope signal; and determining a range to an object based on an electrical signal associated with the reflected signal.
1. A light detection and ranging (LIDAR) system comprising:
a laser source configured to provide an optical signal at a first signal power;
an amplifier having a plurality of gain configurations, wherein the amplifier is configured to receive the optical signal and amplify the optical signal based on a gain configuration of the plurality of gain configurations;
one or more processors configured to:
adjust the gain configuration of the amplifier across two or more of the plurality of gain configurations to cause the amplifier to generate a pulse envelope signal at a second signal power, wherein the second signal power is greater than the first signal power by at least an amount corresponding to an inverse of a duty cycle of the optical signal.
2. The LIDAR system of claim 1 , wherein the amplifier transmits the pulse envelope signal via one or more optical elements.
3. The LIDAR system of claim 2 , further comprising:
a receiver configured to receive a reflected signal responsive to the amplifier transmitting the pulse envelope signal,
wherein the one or more processors are further configured to determine a range to an object based on an electrical signal associated with the reflected signal.
4. The LIDAR system of claim 1 , wherein the pulse envelope signal has a pulse repetition period that is greater than or equal to 1 microsecond and less than or equal to 1 millisecond.
5. The LIDAR system of claim 1 , further comprising:
an electro-optic modulator configured to:
receive the optical signal from the laser source; and
modulate the optical signal prior to the amplifier receiving the optical signal.
6. The LIDAR system of claim 5 , wherein the modulator is an electro-optic modulator, an electro-absorption modulator, or a Mach-Zehnder modulator.
7. The LIDAR system of claim 1 , wherein the laser source modulates the optical signal prior to the amplifier receiving the optical signal.
8. The LIDAR system of claim 1 , wherein the amplifier comprises an erbium doped fiber amplifier (EDFA) or a semiconductor optical amplifier (SOA).
9. The LIDAR system of claim 8 , wherein the amplifier comprises the SOA, and wherein the SOA modulates the optical signal using index modulation.
10. A light detection and ranging (LIDAR) system comprising:
a laser source configured to provide an optical signal at a first signal power;
a pulse envelope generator configured to generate a pulse envelope signal at a second signal power by:
determining a relative phase difference between a first optical signal associated with the optical signal and a second optical signal associated with the optical signal, wherein the second signal power is greater than the first signal power by at least an amount corresponding to an inverse of a duty cycle of the optical signal; and
an amplifier configured to amplify the pulse envelope signal and transmit the amplified pulse envelope signal via one or more optical elements.
11. The LIDAR system of claim 10 , wherein the pulse envelope generator modulates an amplitude of the light signal.
12. The LIDAR system of claim 10 , wherein the pulse envelope generator is an electro-absorption modulator (EAM).
13. The LIDAR system of claim 10 , wherein the pulse envelope generator is configured to:
split the optical signal into the first optical signal and the second optical signal.
14. The LIDAR system of claim 10 , wherein the pulse envelope generator is a Mach-Zehnder modulator.
15. The LIDAR system of claim 10 , wherein the amplifier comprises an erbium doped fiber amplifier (EDFA) or a semiconductor optical amplifier (SOA).
16. A method comprising:
modulating an optical signal at a first signal power to generate a modulated optical signal;
selecting a plurality of pulses from the modulated optical signal to generate a pulsed envelope signal at a second signal power, wherein the second signal power is greater than the first signal power by at least an amount corresponding to an inverse of a duty cycle of the optical signal;
transmitting the pulsed envelope signal via one or more optical elements;
receiving a reflected signal responsive to transmitting the pulsed envelope signal; and
determining a range to an object based on an electrical signal associated with the reflected signal.