Example of the measurement of a highly reflective material, a dielectric multi-layer mirror using absolute reflectance spectroscopy

Dielectric multi-layer mirrors are laminated optics comprising of a combination of high refractive index and low refractive index materials. Using the interference effect, this mirror can provide extremely high reflectance (near 100%) in a specific wavelength range. This type of mirror is widely used in cameras, telescopes and optics for optical communication to reduce loss in light intensity. Therefore, in the quality control and R&D of dielectric multi-layer mirrors, it is very important to evaluate the reflectance with very high accuracy.

Jasco provides a high performance absolute reflectance measurement system using the V-700 series UV/Vis spectrophotometer with double-beam optical system, which has high photometric stability. The absolute reflectance system can perform measurement at arbitrary and user-selectable incident angles; this allows the measurement of dielectric multi-layer mirrors at designated incident angles.

As an example of high reflectance measurement using the Jasco absolute reflectance measurement system, this application note reports the results for a dielectric multi-layer mirror.