Reading voxels in an optical storage medium using off-axis lighting

An optical read system configured for reading data encoded in voxels positioned in sectors within layers in an optical storage medium, comprising:

• a camera comprising a light-sensitive image sensor, the camera having an optical axis that is positioned relative to the optical storage medium such that a field of view (FOV) of the camera is capable of alignment with the layers of the optical storage medium;
• a microscopy objective coupled to the camera having an adjustable depth of focus for controllably focusing on a selected layer of the layers of the optical storage medium, the microscopy objective being aligned along the optical axis of the camera;
• a source of an illumination beam that propagates in the optical storage medium to selectively illuminate voxels in the selected layer of the optical storage medium within the FOV of the camera;
• and
• illumination optics for shaping a cross-sectional profile of the illumination beam into an elliptical shape and positioning the illumination beam for entry at an oblique angle at a bottom surface of the optical storage medium.

An optical read drive for reading data from an optical storage medium containing a plurality of voxels arranged in layers, comprising:

• a line scanning camera comprising an image sensor and shutter, the line scanning camera having a field of view (FOV);
• a laser source configured to provide an illumination beam for illuminating voxels within the FOV of the line scanning camera in a selected layer of the layers of the optical storage medium;
• a microscopy objective coupled to the line scanning camera and being controllably focused on the selected layer of voxels in the optical storage medium, the microscopy objective and the line scanning camera being aligned along a common optical axis that projects into the optical storage medium;
• illumination optics coupled to the laser source for directing the illumination beam to propagate off-axis from the optical axis in the optical storage medium;
• a motorized stage on which the optical storage medium is located, and
• a controller coupled to the motorized stage, the microscopy objective, and the line scanning camera, the controller being configured to synchronize movement of the optical storage medium on the motorized stage with operation of the line scanning camera shutter and the microscopy objective.