Prism coupling systems and methods employing light-blocking members

• Main Authors: BARNES, CRAIG LLEWELLYN, SCHNEIDER, VITOR MARINO, WETMORE, NATHANIEL DAVID
• Format: Patent
• Language: Chinese; English
• Published: 01.04.2023
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

A prism coupling system configured to determine at least one stress characteristic in a chemically strengthened substrate having a surface and a near-surface waveguide has a light source system that generates measurement light. A coupling prism provides optical coupling of the measurement light into and out of the near-surface waveguide over an optical path that comprises a low-angle region and a high-angle region. A detector system arranged to receive the measurement light from the coupling prism to detect a mode spectrum image. A light-blocking member is operably disposed to at least partially extend into the low-angle region without extending into the high-angle region to increase or optimize the contrast of the mode spectrum image.