Which mechanism causes refractive index variations in gradient-index (GRIN) lenses?

💡 Explanation

Birefringence occurs due to the stress-optic effect, because spatially varying stresses induce changes in local density, causing refractive index variation within the GRIN rather than through other mechanisms. Therefore stress-optic gives GRIN properties, rather than absorption.

• Which outcome results when a catalytic converter substrate plugs?
• Which outcome occurs when catalytic converter reaches operating temperature in car exhaust system during cold start?
• Which limitation arises when designing ultra-high bypass turbofan engines?
• Which consequence results when thin-film interference affects optical data storage?
• Which outcome results during reverse Brayton cycle operation?
• Which mechanism accelerates corrosion when stainless steel's chromium concentration falls below a threshold?