Photonics Handbook

Photonics is the study of light and other types of radiant energy whose quantum unit is the photon. The impact of photonics on research, technology, navigation, culture, astronomy, forensics, and...

Developed in the early 1990s, the silicon photomultiplier (SiPM) is a solid-state photodetector whose sensitivity to light rivals that of a photomultiplier tube (PMT) in a regime where a few hundred...

The term fluorescence is often applied as a synonym for photoluminescence, although luminescence actually covers fluorescence and phosphorescence. Both of these terms describe the process of...

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...

An integrating sphere’s function is to spatially integrate radiant flux (light). However, before one can optimize a sphere design for a particular application, it is important to understand how...

The first high-reflectance mirror coatings for the UV and vacuum UV (VUV) were of the Al + MgF2 type produced in the late 1950s. Coatings of this design are still used today for multigas cavity...

What are thin-film coatings? The purpose of any optical thin-film coating is to modify the transmittance and reflectance properties of the substrate material to which they are applied. Most coatings...

One of the most critical elements of any time-resolved spectroscopy and dynamics experiment is the optical delay line. A typical optical delay line consists of a retroreflector or folding mirrors on...

Abbe Error — Linear off-axis errors introduced by angular deviations coupled to a moment arm at the point of interest on stage mounted devices (θ in Figure 1). The effect of Abbe error...

Photonics Rules of Thumb Scientists and engineers tend to want to answer simple relational questions with a blackboard covered with equations, even when questioners just want a rough estimate to...

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...

Lenses come in a variety of shapes, sizes and materials. They can be made of a single piece of glass or have multiple elements; their surfaces can be spherical, aspheric or cylindrical; they can be...

For any discussion of laser beam diagnostics, it is first necessary to define some terms that characterize beam properties. Broad definitions can include measurements of laser energy or power,...

The applications where rapid detection of light is a must are many. They include a wide variety: semiconductor inspection, gene sequencing, oil well logging and high-energy physics. The reasons for...

An indicator of how well the entire system performs is a measurement called bit-error-ratio (BER). Acceptable BERs range from one error per billion to one per trillion bits transmitted. It is rare...

There are three fundamentally different dispersive phenomena in optical fiber, of which polarization mode dispersion (PMD) is the most complex. In digital multimode fiber systems, a light pulse...