Compact apparatus providing multi-dimensional characterization of spherical objects using coherent light

An apparatus, comprising:

• a compact package having a first portion and a second portion, wherein the first portion has a first opening, and the second portion has a second opening, wherein the first opening is at an angle with respect to the second opening;
• a first transmitter inside the compact package to generate a first pair of coherent beams at a first wavelength, wherein the coherent beams of the first pair have substantially high pointing stability and propagate along a first axis through the first opening in the first portion and cross each other outside the compact package at a first angle in a first plane to form a sample volume to illuminate a spherical object;
• a receiver inside the compact package to measure through the second opening in the second portion a phase of a first scattered light from the spherical object, the receiver comprises three photodetectors to sense a first scattered light to measure a first velocity component;
• a movable computer-controlled slit aperture inside the package in front of the receiver to adjust aperture based on the spherical object arrival rate;
• and
• a real time signal-processing unit inside the package coupled to the receiver to determine the size and a velocity component of the spherical object from the phase of the scattered light.

A system comprising:

• a compact package having a first portion and a second portion, wherein the first portion has a first opening, and the second portion has a second opening, wherein the first opening is at an angle with respect to the second opening;
• a first laser inside the compact package to generate a first pair of substantially stable coherent beams at a first wavelength;
• a first free-space optics inside the compact package coupled to the first laser to guide the coherent beams through the first opening in the first portion in such a way that the coherent beams cross each other outside the compact package at a first angle to form a sample volume to illuminate a spherical object;
• a first frequency modulator coupled to the first laser and to the first free-space optics to modulate one of the coherent beams;
• a collecting optics inside the compact package to collect a light scattered from the spherical object;
• three spaced apart photodetectors inside the compact package coupled to the collecting optics to sense the scattered light collected by the collecting optics through the second opening in the second portion;
• a phase measurement unit coupled to the three photodetectors to measure the phase of the scattered light, wherein the first laser, the first free-space optics, the first frequency modulator, the collecting optics, the three spaced apart photodetectors, and the phase measurement unit are inside the compact package;
• and
• a signal-processing unit coupled to the phase detector unit to determine a size and a first velocity component of the spherical object.