Glossary

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Warm-Up Time

The time required by a laser to reach a designated percentage of the final output power (typically 95%).

See also Laser

Wavelength

The peak to peak distance covered by one cycle of an electromagnetic wave. It is inversely related to frequency. The longer the wavelength, the lower the frequency; conversely, the shorter the wavelength, the higher the frequency.

Wedge Angle

A small angle of incline between two faces in a wedge element.

White Balance

A function in cameras that allows for calibration of colors in different lighting conditions using a reference white.

Wide-Field Eyepiece

A type of eyepiece design consisting of one achromatic doublet lens and one plano-convex lens whose convex surfaces face each other. It creates a field of view greater than 50°, hence the wide-field denotation in the name. It is designed for use with high power achromatic objectives.

See also Huygenian Eyepiece, Achromatic Objective, Kellner Eyepiece, Periplan Eyepiece

Wire Grid Polarizer

A type of polarizer consisting of a thin layer of aluminum MicroWires™ sandwiched between two glass windows. It reflects S-polarized light while transmitting P-polarized light and offers a higher transmission level and higher maximum operating temperature compared to glass and film linear polarizers.

See also P-Polarization, Linear Polarizer, S-Polarization, Polarization

Wobble

Generally defined with reference to a rotation stage, the measure of the tilting of a rotation stage's platform frequently caused by the axis of rotation not being perpendicular to the platform.

Working Distance (WD)

The distance from the front end of a lens system to the object under inspection.

See also Doubler Tube, Depth of Field (DOF)

Worm Gear Drive

A type of drive mechanism for rotary stages in which a worm wheel (gear) attached to the stage shaft meshes with the worm drive, whose shaft extends out of the housing. Controlled rotation of the worm shaft creates precise angular rotation of the worm wheel and stage shaft. The worm gear and shaft are matched sets and are pre-loaded to remove backlash.

WRATTEN Filter

A type of filter created by dissolving organic dyes in a gelatin material to achieve the desired spectral performance. The gelatin liquid and dye combination is then coated onto a supportive substrate until it has dried. After removal from the substrate, the film is coated with laquer for protection. Although the filters are coated, they should be handled only by the edges or in the corners to avoid damage.

See also Filter