Photonics Handbook

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...

Density – % Transmission (Opacity x % Transmission = 100) Density Opacity %T 0 1.0 100 0.1 1.3 80 0.2 1.6 63 0.3 2.0 50 0.4 2.5 40 0.5 3.2 32 0.6 4.0 25 0.7 5.0 20 0.8 6.3 16 0.9 8.0 13...

Excimers are pulsed gas lasers that deliver high output power and pulse energies in the ultraviolet and deep-ultraviolet wavelengths. This enables them to power applications that cannot be supported...

Since their invention in the late 1960s, charge-coupled devices, also called CCDs, have found widespread use in imaging applications. Electronic cameras based on CCD technology are used in...

Optical coatings are deposited as thin-film multilayers of a variety of materials using specific deposition techniques. Coatings are applied to optical components that are intended for use at...

Some efforts in global optimization research for optical design center around probabilistic methods such as global search. While promising for small problems with few variables, these methods...

Unlike an edge emitter, a VCSEL has a maximum operating power that is not limited by catastrophic optical damage of the exit aperture because its aperture is larger and its PN junction does not...

In the search for ever-higher pixel counts for the digital still camera, it is clear that, if chip size remains constant, then “more pixels” means “smaller pixels.” The...

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...

As bit rates increase to meet expanding demand, systems have become increasingly sensitive to polarization-related impairments. These include polarization mode dispersion (PMD) in optical fibers,...

In the beginning, automated inspection focused on the camera and optics, the algorithms, the interface hardware and the processor. Only rarely was attention paid to the lighting system or lighting...

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...

Early fiber lasers were inefficient and limited to low powers, until more effective methods emerged to deliver the pump light into the cladding. Valentin Gapontsev, founder and CEO of IPG Photonics,...

Except for direct illumination from the sun, laser, or other light source, everything we see or detect is ultimately scattered light. Light can be scattered or rescattered during its propagation to...

The benefits of aspheric lenses are numerous: They allow for a reduction in spherical aberrations and are ideal for focusing or collimating light, as they can achieve a low ƒ-number. Aspheres...

Prefixes for Binary Multiples The International Electrotechnical Commission (IEC) in 1998 approved as an IEC International Standard names and symbols for prefixes for binary multiples for use...

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...

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...

Given the pace at which technology advances, there always seems to be a learning curve. With the abundance of consumer electronics available, there typically is no right or wrong way to use these...

With the understanding of aspheric lens manufacturing provided in part one of this article, designers have the tools to optimize their aspheres; the next step is to understand how to specify and...

Optical fibers are made from either glass or plastic. Most are roughly the diameter of a human hair, and they may be many miles long. Light is transmitted along the center of the fiber from one end...

Light is a versatile tool for investigating physical and chemical processes in nature. Any specific system being analyzed may, through the light it emits or reflects, communicate information about...

Optical design software allows the user to develop a configuration of optical elements that manipulate the trajectory of light for the purposes of creating an image, illuminating a target, coupling...

A bench power supply should be thoroughly tested and characterized before it is used to power a laser. The quality of the controls and safety measures incorporated into a bench supply will need to be...

Laser development for the microscopy market continues to be driven by key trends in applications, which currently include superresolution techniques, multiphoton applications in optogenetics and...

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...

Double-sided processing is a batch-type process that uses planetary action — generally with loose, abrasive particles suspended in a liquid vehicle — to abrade material almost equally...

International System of Units (SI) SI Prefixes Multiples Factor Name Symbol 1024 yotta Y 1021 zetta Z 1018 exa E 1015 peta P 1012 tera T 109 ...

In their earliest forms, UV bandpass filters that were optimized for wavelengths less than 400 nm, such as the Schott UG or the Hoya U-series, were constructed of absorbing compounds in glass. Such...

Table of the Greek alphabet and what the letters are commonly used to designate. Name Capital Small Commonly Used to Designate Alpha A α Angles, coefficients, attenuation constant,...

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...

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 wavelength range of commercially available LEDs with single-element output power of at least 5 mW is 275 to 950 nm. Each wavelength range is made from a specific semiconductor material family,...

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...

Over 60 years have passed since the first demonstration of a laser in 1960. After the initial spark of interest, lasers were for a while categorized as “a solution waiting for a problem,”...

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...

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...

To order a copy of the latest printed version of the Photonics Spectrum Reference Chart, visit our bookstore at www.Photonics.com/wallchart.

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...

If we were to estimate the output of a CCD or thermal camera, we would typically draw an image over the detectors, aligning the image with the detector axes. We show it this way because it’s...

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...

Optics can be contaminated in many ways. Contamination can be kept to a minimum by returning the optics to their case after use or by covering the optics for protection from the outside environment....

Equation (1) is known as the Gaussian form of the lens equation, after the mathematician Karl F. Gauss. Equation (2), first derived by Sir Isaac Newton, is the Newtonian form of a lens equation. The...

The digital camera represents an integration of optics, mechanics and electronics consisting of three layers (Figures 1a, b and c). The top and the middle layers are printed circuit boards (PCBs),...

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...

An optical coating engineer is frequently confronted with a difficult specification for a coating. Often the difficulty in the specification results from the particular form of the optical system. If...