Photonics Handbook

As recently as five years ago, shopping for a microscope light source was fairly straightforward. For routine applications, it was tungsten halogen, typically 100 W, while for fluorescence, it was an...

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...

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...

Electrical engineers are very familiar with the effects of shot noise, thermal noise, flicker noise and crosstalk, and recognize how these effects can reduce the signal-to-noise ratio (SNR) in their...

Silicon photonics is widely considered a key enabling technology for further development of optical interconnect solutions needed to address growing traffic on the internet. From the first submarine...

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...

Technological advances have resulted in new, higher-quality sensors that enable machine vision cameras to deliver greater features and functionality at a lower cost than ever before. These factors...

Since its first successful operation in 1960 at Hughes Research Labs, the laser technology has been at the center of innovation and research. Semiconductor lasers first made their appearance in 1962...

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...

By its original definition, a nanopositioning device is a mechanism capable of repeatedly delivering motion in increments as small as one nanometer. Lately demands from industry and research have...

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...

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...

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...

As you operate your laser, only a portion of the electrical power sourced from your laser driver converts to light energy. The remainder turns to heat, and the buildup of that thermal energy presents...

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...

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,...

The optical materials selected for an optical system depend upon the application, the required system performance and the environment in which the system is to perform; thus the materials’...

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...

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...

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...

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,”...

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...

Any number of medical, industrial, and analytical applications requires the detection of light. Chemiluminescence, bioluminescence, fluorescence, and atomic absorption are just a few, and all require...

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...

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...

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...

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...

An optical time-domain reflectometer sends short pulses of light into a fiber and measures its reflections as a function of time. The delay of these reflections to the detector as well as their...

The ubiquitous Nd:YAG laser has played many roles over the years. For the military, it has provided rangefinding and target designation capabilities. When used with nonlinear optics or as a pump...

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...

Photonic components are key elements for the information technology (IT). Photonics technology covers the generation of information (cameras, sensors), its transportation (optical communication),...

Reflected-ultraviolet imaging is a rather mysterious area of the imaging field. There is relatively little actual UV imagery to be found on the Internet or in the literature compared to near-infrared...

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...

Illumination design has developed rapidly to include not only automotive headlamps and street lamps, but also backlit displays, fluorescent panel lighting, light-emitting diode or laser sources, and...

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....

Manufacturing the laser diode is complicated by the existence of multiple proprietary techniques and intellectual property barriers together with complex device physics and unique materials. ...

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 basic difference between the household mirror and the optical mirror is that one is coated on the back surface and the other is coated on the front. For optical applications, a front-surface...

Just as an electronic connector provides a pluggable connection between electronic circuits, a fiber optic connector provides an optical one. The goal is joining a fiber to a transmitter, receiver or...

Spectral selection is a powerful tool that enhances conventional imaging tremendously. Most imaging systems, including the human eye, are designed to image light over a broad range of the spectrum....

Applications facilitated by tunable lasers fall into two categories: situations in which one or more discrete wavelengths are not available from any single- or multiline fixed-wavelength laser, or...

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...

By observing a few simple rules that govern diode lasers’ properties, driving them loses much of its mystery. Below its threshold current, a diode laser emits LED light with spontaneous...

Optics today needs alchemy, and the forces that motivate microchip technology are a key reason why. Today, light can transmit and process digital information as well as electricity can — in...

Reading and writing systems for polygonal scanners differ in the use of the scanner. However, many performance characteristics are similar for both. In writing applications, a light source, usually a...

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,...

In the three decades since its introduction, the CO2 laser has become the workhorse of industrial lasers. Today it is available in a range of designs and sizes with output powers of 20 kW and more....

To Isaac Newton the problem was clear, and in 1704 he realized the effects of atmospheric turbulence on image formation. Just as heat waves shimmering above a hot patch of ground can distort our...

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...