Test & Measurement Articles

When evaluating the surface of a component, surface roughness can be assessed by eye or by rubbing it with a fingertip. Common expressions include “shiny,” “lusterless and...

Profiling beams under 10 µm in size is one of the more challenging beam profiling applications. There are numerous reasons for this, including the very small size. Focal plane arrays commonly...

Surface quality has become one of the most poorly understood specifications in the optics industry. A significant portion of the confusion stems from the two major competing (and largely...

An interferometer is an instrument that compares the position or surface structure of two objects. The basic two-beam division of amplitude interferometer components consists of a light source, a...

Designing devices that incorporate ultrathin films is an important means of enhancing yields. However, characterizing ultrathin films provides a challenge for mainstream metrology tools such as...

That portion of the spectrum that the eye can see — and its rainbow of colors — is rather small, covering approximately 360 to 830 nm. What colors we perceive depends on wavelength, while...

Intensity and uniformity can be described using different physical attributes, which makes interpreting requirements somewhat confusing. This article intends to provide an explanation and serve as a...

Radiometry involves several activities. The two most common are the description and measurement of optical radiation, and, starting with the knowledge of some aspects of optical radiation at one...

The market for flat panel displays (FPDs) has undergone tremendous growth, driven mostly by increased demand for televisions, cell phones, computers, digital cameras and MP3 players. Similarly,...

All optical spectrometry techniques rely on the measurement of radiant power. The configuration of the instrument varies based on the measurement technique: absorption, emission, luminescence, or...

Conditions on the factory floor and in industrial cleanrooms with high-capacity air filtration systems can hamper the use of interferometry. Another problem is the testing of large-aperture mirrors...

NSOM is suitable for studies on the mesoscopic scale (several tens to hundreds of molecular dimensions). It has become an important tool in research and applications of semiconductors, organic layers...

Particle image velocimetry (PIV) is an experimental tool in fluid mechanics and aerodynamics. The basic principle involves photographic recording of the motion of microscopic particles that follow...

The scope of optical spectroscopic instrumentation is indeed very broad. Many analytical methods rely on the interaction of radiation with matter and are often described in the context of quantum and...