Why Power Spectral Density (PSD) Is So Valuable

In the realm of high-precision optics, particularly those employed in high-energy laser applications, the quality of optical surfaces is paramount. Traditional metrics like Peak-to-Valley (PV) and Root Mean Square (RMS) roughness provide an overall assessment of surface smoothness but fall short in offering detailed insights into surface imperfections that could affect performance.

Power Spectral Density (PSD) is a transformative approach that decomposes surface texture into its constituent spatial frequencies, providing a granular analysis of surface quality. By using PSD, engineers can better understand and control surface roughness at different scales, ensuring optimal performance and reliability of optical systems. This article delves into the significance of PSD in enhancing the precision and efficiency of high-energy laser optics, illustrating why it is a superior method for surface characterization and specification.