Detecting peak laser pulses using control signal timings

1. A system for detecting a peak laser pulse, comprising:

a laser;

a photodiode configured to detect pulses emitted by the laser; and

circuitry configured to:

receive a periodic series of voltage signals based on laser pulses detected by the photodiode;

stretch the voltage signals;

obtain sampled voltages from the stretched voltage signals using periodic control signals;

shift the timing of the periodic control signals;

count a number of pulses for each respective control signal timing shift;

compare the sampled voltages for respective timings of the control signals; and

select an optimal control signal timing based on the comparison and based on counts for respective control signal timing shifts.

2. The system of claim 1 , wherein:

the circuitry configured to stretch the periodic voltage signals comprises an integrating circuit; and

the circuitry configured to shift the periodic control signals is configured to shift the control signals by a number of time steps.

3. The system of claim 1 , wherein the circuitry configured to obtain sampled voltages from the stretched voltage signals is configured to hold the sampled voltages for a time duration.

4. The system of claim 1 , wherein the circuitry configured to select an optimal control signal timing shift is configured to select the control signal timing shift associated with a highest sampled voltage.

5. The system of claim 1 , wherein the circuitry is configured to configured to shift the timing of the control signal by a number of time steps, and obtain the sampled voltages in parallel up to a last time step.

6. The system of claim 1 , wherein the laser pulses have a pulse width in the range of 300 femtoseconds to 1.2 picoseconds.

7. An apparatus comprising circuitry configured to:

receive a periodic series of voltage signals based on laser pulses detected by a photodiode;

stretch the voltage signals;

obtain sampled voltages from the stretched voltage signals using periodic control signals;

shift the timing of the periodic control signals;

compare the sampled voltages for respective timings of the control signals;

count a number of pulses for each respective control signal timing shift; and

select an optimal control signal timing based on the comparison and based on counts for respective control signal timing shifts.

8. The apparatus of claim 7 , wherein:

the circuitry is configured to stretch the periodic voltage signals using an integrating circuit; and

the circuitry configured to shift the periodic control signals is configured to shift the control signals by a time step.

9. The apparatus of claim 7 , wherein the circuitry configured to obtain sampled voltages from the stretched voltage signals is configured to hold the sampled voltages for a time duration.

10. The apparatus of claim 7 , wherein the circuitry configured to select an optimal control signal timing shift is configured to select the control signal timing shift associated with a highest sampled voltage.

11. The apparatus of claim 7 , wherein the circuitry is configured to shift the timing of the control signal by a number of time steps, and obtain the sampled voltages in parallel up to a last time step.

12. The apparatus of claim 7 , wherein the laser pulses have a pulse width in the range of 300 femtoseconds to 1.2 picoseconds.

13. A method for detecting a peak pulse emitted by a laser, comprising:

receiving a periodic series of voltage signals based on laser pulses detected by a photodiode, the laser pulses having a pulse width in the range of 300 femtoseconds to 1.2 picoseconds;

stretching the voltage signals;

counting a number of pulses for each respective timing shift;

obtaining a set of sampled voltages from the stretched voltage signals using a set of shifted control signals, each shifted control signal having a respective timing shift from the other control signals;

determining an optimal control signal timing based on a comparison of the sampled voltages for each of the timing shifts; and

selecting a timing shift for the control signals based on counts for the respective timing shift.

14. The method of claim 13 , wherein stretching the voltage signals comprises providing the series of voltage signals to an integrating circuit.

15. The method of claim 13 , wherein obtaining the sampled voltages comprises holding the sampled voltages for a time duration.

16. The method of claim 13 , wherein determining an optimal control signal timing comprises selecting the timing shift for the control signals associated with highest sampled voltages.

17. The method of claim 13 , wherein the set of sampled voltages are obtained in parallel.