Explore how higher frequency THz waves (>300 GHz) can be used to detect small defects embedded within solid matrices such as lyocakes, crucial components in pharmaceutical manufacturing. Employed in a transmission geometry with a tightly focused THz beam, our innovative approach facilitates penetration through primary packaging (e.g., glass vials). The contrast in the resulting images, derived from transmission losses due to defect presence, underscores the effectiveness of our system's design. This achievement is made possible by advanced data analysis techniques, integral to processing collected information for precise defect identification and characterization within the solid matrices.

Detecting defects within the solid matrix of lyocakes presents a formidable challenge due to their opaque nature, rendering conventional inspection methods inadequate. Presently, visual inspections conducted by humans can only identify defects on the outer surface of lyocakes. We revolutionize this process by penetrating the opaque lyocake and detecting foreign particles, such as glass particles, with remarkable precision. Capable of detecting particles as small as 1 mm (in diameter) deep inside lyocakes, we offer unparalleled insight into product quality and safety. The accompanying illustrated image demonstrates the detection of a spherical defect nestled at the bottom of a vial, showcasing the technical prowess and effectiveness of our THz solution in enhancing quality control measures.