Methods for modulating an intensity profile of a laser beam and systems for same
Aspects of the present disclosure include methods for modulating an intensity profile of a laser beam. Methods according to certain embodiments include irradiating an acousto-optic device with a laser to generate an output laser beam having a plurality of angularly deflected laser beams, capturing an image of the output laser beam, determining an intensity profile of the output laser beam along a horizontal axis from the captured image and adjusting one or more parameters of a waveform inputted into the acousto-optic device in response to the determined intensity profile to generate an output laser beam having a modulated intensity profile. Systems having a laser, an acousto-optic device, an imaging sensor and a waveform generator as well as non-transitory computer readable storage medium with instructions for practicing the subject methods are also described.
1. A method for modulating an intensity profile of a laser in a particle analyzer, the method comprising:
irradiating an acousto-optic device with a laser to generate an output laser beam comprising a plurality of angularly deflected laser beams;
capturing an image of the output laser beam;
determining an intensity profile of the output laser beam along a horizontal axis from the captured image; and
adjusting one or more parameters of a waveform inputted into the acousto-optic device in response to the determined intensity profile to generate an output laser beam having a modulated intensity profile.
2. The method according to claim 1 , wherein the method comprises adjusting one or more tones of the inputted waveform.
3. The method according to claim 2 , wherein each tone of the inputted waveform comprises one or more sine waves.
4. The method according to claim 2 , wherein the method comprises adjusting an amplitude of the one or more tones of the inputted waveform.
5. The method according to claim 1 , wherein the method further comprises:
determining an amplitude of each angularly deflected laser beam in the output laser beam;
adjusting one or more parameters of the waveform inputted into the acousto-optic device for each angularly deflected laser beam.
6. The method according to claim 5 , wherein the method comprises adjusting the amplitude of the tone of the inputted waveform for each angularly deflected laser beam.
7. The method according to claim 5 , wherein the method comprises adjusting the frequency of the tone of the inputted waveform for each angularly deflected laser beam.
8. The method according to claim 1 , wherein one or more parameters of the inputted waveform are adjusted to generate an output laser beam having a substantially constant intensity profile along a horizontal axis.
9. The method according to claim 8 , wherein one or more parameters of the inputted waveform are adjusted to generate a plurality of angularly deflected laser beams having intensities which vary by 10% or less.
10. The method according to claim 8 , wherein one or more parameters of the inputted waveform are adjusted to generate a plurality of angularly deflected laser beams having intensities which vary by 5% or less.
11. The method according to claim 1 , wherein the method further comprises generating an intensity profile plot from the captured image of the output laser beam.
12. The method according to claim 1 , wherein the acousto-optic device is an acousto-optic deflector.
13. The method according to claim 1 , wherein each waveform inputted into the acousto-optic device is generated with an Arbitrary Waveform Generator (AWG).
14. The method according to claim 1 , wherein the plurality of angularly deflected laser beams comprise a local oscillator (LO) beam and a plurality of radiofrequency comb beams.
15. The method according to claim 1 , wherein the plurality of angularly deflected laser beams are spatially separated.
16. The method according to claim 15 , wherein the each angularly deflected laser beam at least partially overlaps with one other angularly deflected laser beam in the output laser beam.
17. The method according to claim 1 , wherein the particle analyzer is part of a flow cytometer.
18. A particle analyzer comprising:
a laser;
an acousto-optic device;
a waveform generator configured to input a waveform into the acousto-optic device to generate an output laser beam comprising a plurality of angularly deflected laser beams;
an imaging photosensor; and
a controller comprising a processor having memory operably coupled to the processor wherein the memory comprises instructions stored thereon, which when executed by the processor, cause the processor to:
capture an image of the output laser beam with the imaging photosensor;
determine an intensity profile of the output laser beam along a horizontal axis from the captured image; and
adjust one or more parameters of a waveform inputted into the acousto-optic device in response to the determined intensity profile to generate an output laser beam having a modulated intensity profile.
19. The particle analyzer according to claim 18 , wherein the acousto-optic device is an acousto-optic deflector.
20. The particle analyzer according to claim 18 , wherein the imaging photosensor is a camera.