Optics Articles

Diffraction gratings are optical components with a periodic structure that separate light into beams traveling in predictable directions based on their wavelength. The grating acts as the dispersive...

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...

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...

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...

Flat optics generally perform three main functions: They transmit light (windows), reflect light (mirrors), and fold light (prisms). While most optical manufacturers make spherical and flat optics, 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...

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...

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...

For rotationally symmetric optical systems, either the lens or the detector moves along the optical axis to maintain optical performance. If the compensating axial motion is accomplished without the...

ACOUSTO-OPTIC SCANNING DEVICES: CHARACTERISTICS MODULATORS Material Bandwidth (MHz) Rise Time (ns) Acousto Input Power (W) (Saturation) Material Wavelength Range...

Ultraprecision machining can be defined in general terms as the removal of material from a substrate utilizing a machine tool that operates at a resolution of 10 nm (0.4 μin.) or less. The...

Attentuation Region (or Blocking) The spectral region over which very low transmission is required. Attenuation requirements are generally specified in percent transmission over a given spectral...

A lens collects light from a point on an object and focuses it to a corresponding conjugate point on an image. Under most conditions, the lens fails at this task because of some error in the...

Camera resolution depends upon the optical blur diameter and the detector size. Schade combined these to create an equivalent resolution that is a function of Fλ/d where F is the focal ratio,...

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...

With a specific gravity of 1.85 g/cm3, beryllium is the lightest metal that is workable. It is 45 percent lighter than aluminum and approximately five times as stiff. Its stiffness to weight ratio...

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...

To the novice or casual user of optics, the acquisition of an optical system can be a very difficult experience. Failure to understand the ground rules can result in unnecessarily high cost, late...

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...

Plate beamsplitters Plate beamsplitters consist of a thin plate of optical crown glass with a different type of coating deposited on each side. The first surface is coated with an all-dielectric...

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...

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...

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...