Phased-array beam steering for materials processing
A system includes a multi-channel beam splitter arranged and configured to split an input optical signal into a plurality of split optical signals; a plurality of phase modulators, wherein each phase modulator of the plurality of phase modulators is operative to modify a phase of a corresponding split optical signal of the plurality of split optical signals in response to a control signal; a waveguide arranged at an optical output of the plurality of phase modulators, the waveguide configured to spatially-rearrange the split optical signals output from the plurality of phase modulators into a pattern, thereby producing an optical signal pattern; and an optical amplifier arranged at an optical output of the waveguide, wherein the optical amplifier is configured to amplify the optical signal pattern produced by the waveguide.
1. A beam steering system for materials processing, the system comprising:
a multi-channel beam splitter arranged and configured to split an input optical signal into a plurality of split optical signals;
a plurality of phase modulators, wherein each phase modulator of the plurality of phase modulators is operative to modify a phase of a corresponding split optical signal of the plurality of split optical signals in response to a control signal;
a waveguide arranged at an optical output of the plurality of phase modulators, the waveguide configured to spatially-rearrange the split optical signals output from the plurality of phase modulators into a pattern such that the split optical signals are coherently combinable into a combined optical signal;
an optical amplifier arranged at an optical output of the waveguide, the optical amplifier configured to amplify the spatially-rearranged split optical signals output by the waveguide, thereby outputting an optical beam including the combined optical signal;
a harmonic conversion module arranged and configured to modify a wavelength of the combined optical signal; and
a lens arranged between the optical amplifier and the harmonic conversion module, wherein the lens is configured to collimate light in the combined optical signal received at the harmonic conversion module.
2. The system of claim 1 , further comprising:
a beam splitter arranged at an optical output of the optical amplifier, the beam splitter configured to transmit a first portion of the combined optical signal output by the optical amplifier and reflect a second portion of the combined optical signal output by the optical amplifier; and
a photodetector arranged to receive the second portion of the combined optical signal and output a corresponding detection signal.
3. The system of claim 2 , further comprising control circuitry communicatively coupled to an output of the photodetector and to an input of each of the plurality of phase modulators, wherein the control circuitry is configured to generate and output the control signal.
4. The system of claim 3 , further comprising an amplitude modulator operative to modulate an amplitude of the input optical signal in response to a control signal, wherein the multi-channel beam splitter is arranged at an optical output of the amplitude modulator.
5. The system of claim 4 , wherein the amplitude modulator and the multi-channel beam splitter are located within a common photonic integrated circuit.
6. The system of claim 4 , wherein the control circuitry is configured to output a control signal to each of the plurality of phase modulators to effect, in combination with the configuration of the pattern of the waveguide, phased-array beam steering at the optical output of the waveguide.
7. The system of claim 3 , wherein the control circuitry is configured to output a control signal to the plurality of phase modulators based, at least in part on the detection signal, to stabilize the phases of the split optical signals output from the optical amplifier.
8. The system of claim 1 , wherein the plurality of phase modulators and the waveguide are located within a common photonic integrated circuit.
9. The system of claim 1 , further comprising a seed laser arranged and configured to generate the input optical signal.
10. The system of claim 1 , wherein the number of phase modulators in the plurality of phase modulators is greater than 100.
11. The system of claim 1 , further comprising a beam positioning system arranged and configured to deflect the combined optical signal output from the harmonic conversion module.
12. The system of claim 11 , wherein the beam positioning system includes at least one selected from the group consisting of an acousto-optic deflector, an electro-optic deflector, a galvanometer mirror scanner and a rotating polygon scanner.
13. The system of claim 1 , wherein each of the plurality of phase modulators is additionally operative to modify an amplitude of a corresponding split optical signal of the plurality of split optical signals in response to a control signal.
14. The system of claim 1 , wherein each of the plurality of phase modulators is provided as a Mach-Zehnder modulator.
15. A beam steering system for materials processing, the system comprising:
a multi-channel beam splitter configured to split an input first optical signal and an input second optical signal into a plurality of split first optical signals and a plurality of split second optical signals, respectively, wherein the input first optical signal has a first wavelength and the input second optical signal has a second wavelength different from the first wavelength;
a plurality of phase modulators arranged at an optical output of the multi-channel beam splitter, wherein each phase modulator of the plurality of phase modulators is operative to modify a phase of a corresponding split first optical signal of the plurality of split first optical signals and operative to modify a phase of a corresponding split second optical signal of the plurality of split second optical signals in response to a control signal;
a waveguide including an optical input optically coupled to an optical output of the plurality of phase modulators and an optical output arranged in a predetermined pattern such that the plurality of split first optical signals are coherently combinable into a combined first optical signal and the plurality of split second optical signals are coherently combinable into a combined second optical signal; and
an optical amplifier arranged at the optical output of the waveguide, the optical amplifier configured to amplify the spatially-rearranged split first optical signals output by the waveguide, thereby outputting an optical beam including the combined first optical signal and the combined second optical signal.
16. The system of claim 15 , further comprising a reference laser configured to generate the input second optical signal.
17. The system of claim 16 , wherein the second optical signal has a second wavelength that is different from a wavelength of the first optical signal.
18. The system of claim 15 , further comprising a dichroic mirror arranged and configured to reflect the combined second optical signal of the optical beam and transmit the combined first optical signal of the optical beam.
19. The system of claim 18 , further comprising a photodetector arranged to receive the combined second optical signal reflected by the dichroic mirror and output a corresponding detection signal.
20. The system of claim 19 , further comprising control circuitry communicatively coupled to an output of the photodetector and to an input of each of the plurality of phase modulators, wherein the control circuitry is configured to generate and output the control signal to the plurality of phase modulators based, at least in part on the detection signal, to stabilize the phases of the split second optical signals output from the plurality of phase modulators.
21. The system of claim 15 , wherein the optical amplifier is configured to amplify the plurality of split first optical signals output by the waveguide selectively with respect to the plurality of split second optical signals.