A method to provide multi-beam imaging of particles, comprising: generating a plurality of light beams comprising a first light beam and a second light beam that converge with each other to form a measurement volume within a particle field using a plurality of vertical cavity surface emitting laser arrays comprising a first vertical cavity surface emitting array and a second vertical cavity surface emitting array , wherein the first vertical cavity surface emitting array comprises a first plurality of vertical cavity surface emitting lasers that generate the first light beam and the second vertical cavity surface emitting array comprises a second plurality of vertical cavity surface emitting lasers that generate the second light beam that converges with the first light beam at an intersection angle to provide uniformity in a background illumination of the measurement volume on an image plane of an imaging system; monitoring the uniformity of the background illumination of the measurement volume on the image plane of the imaging system ; adjusting an angle of at least one of the first plurality of vertical cavity surface emitting lasers of the first vertical cavity surface emitting array based on the monitoring to increase the uniformity of the background illumination of the measurement volume on the image plane of the imaging system; and obtaining, by a digital camera , a first shadow image of a first particle passing through the measurement volume at a focal plane of the digital camera based on the adjusting , wherein the intersection angle of the first light beam and the second light beam is adjusted to remove shadow images of other particles outside the measurement volume . generating a plurality of light beams comprising a first light beam and a second light beam that converge with each other to form a measurement volume within a particle field using a plurality of vertical cavity surface emitting laser arrays comprising a first vertical cavity surface emitting array and a second vertical cavity surface emitting array , wherein the first vertical cavity surface emitting array comprises a first plurality of vertical cavity surface emitting lasers that generate the first light beam and the second vertical cavity surface emitting array comprises a second plurality of vertical cavity surface emitting lasers that generate the second light beam that converges with the first light beam at an intersection angle to provide uniformity in a background illumination of the measurement volume on an image plane of an imaging system; monitoring the uniformity of the background illumination of the measurement volume on the image plane of the imaging system ; adjusting an angle of at least one of the first plurality of vertical cavity surface emitting lasers of the first vertical cavity surface emitting array based on the monitoring to increase the uniformity of the background illumination of the measurement volume on the image plane of the imaging system; and obtaining, by a digital camera , a first shadow image of a first particle passing through the measurement volume at a focal plane of the digital camera based on the adjusting , wherein the intersection angle of the first light beam and the second light beam is adjusted to remove shadow images of other particles outside the measurement volume . <EOS>