Photonics Dictionary: O

A coarse diffraction grating that is used to form a scale of intensities to determine the relative magnitudes of stars. The grating is placed over the objective of a telescope to form a diffraction...

Optical artifacts refer to undesired or unintended effects that can occur in optical systems, such as microscopes, cameras, telescopes, and other optical instruments. These artifacts can distort or...

The phenomenon that can render an optical resonator the equivalent of a semiconductor flip-flop. A bistable device will remain stable in two optical states, one of high transmission and another of...

Optical coherence tomography (OCT) is an imaging technique used in medical diagnostics and biomedical research to obtain high-resolution, cross-sectional images of biological tissues. An OCT imaging...

A measure of the transmittance through an optical medium. Optical density equals the log to the base 10 of the reciprocal of the transmittance. where τλ is transmittance. In spectroscopy,...

In dry etching, a method of characterizing the composition of solid materials such as metal. Atoms in the OES technique are excited by energy that comes from a spark formed between the sample and an...

An optical filter is a device that selectively transmits or blocks specific wavelengths, or colors, of light. Optical filters are used to control the spectral content of light in various...

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial domain representation of an image into its corresponding frequency domain...

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or integrity of the transmitted information. This type of noise is particularly...

Optical parametric amplification (OPA) is a process in nonlinear optics where a weak signal beam is amplified by a much stronger pump beam through the nonlinear interaction in a nonlinear optical...

Optical perturbation refers to any disturbance or alteration in the characteristics of light as it propagates through or interacts with a medium. This perturbation can include changes in the...

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and characteristics of optical components, systems, and devices. These instruments play a...

An optical time-domain reflectometer (OTDR) is a specialized instrument used in optical fiber communications to characterize and analyze the optical fibers' characteristics, including attenuation,...

Optical tweezers refer to a scientific instrument that uses the pressure of laser light to trap and manipulate microscopic objects, such as particles or biological cells, in three dimensions. This...

Optoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light and its interactions with different materials. The term "optoelectronics" is...