An optical instrument is a device that processes

light wave In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength, ra ...

s (or

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can ...

s), either to enhance an image for viewing or to analyze and determine their characteristic properties. Common examples include

periscope A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position. In its simplest form, it consists of an outer case with ...

microscope A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic ...

telescope A telescope is a device used to observe distant objects by their emission, Absorption (electromagnetic radiation), absorption, or Reflection (physics), reflection of electromagnetic radiation. Originally, it was an optical instrument using len ...

s, and

camera A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photograp ...

Image enhancement

The first optical instruments were

s used for magnification of distant images, and

s used for magnifying very tiny images. Since the days of

Galileo Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei ( , , ) or mononymously as Galileo, was an Italian astronomer, physicist and engineer, sometimes described as a poly ...

and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the

electromagnetic spectrum The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high ...

. The binocular device is a generally compact instrument for both eyes designed for mobile use. A

could be considered a type of optical instrument, with the

pinhole camera A pinhole camera is a simple camera without a lens but with a tiny aperture (the so-called ''Pinhole (optics), pinhole'')—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects a ...

and

camera obscura A camera obscura (; ) is the natural phenomenon in which the rays of light passing through a aperture, small hole into a dark space form an image where they strike a surface, resulting in an inverted (upside down) and reversed (left to right) ...

being very simple examples of such devices.

Analysis

Another class of optical instrument is used to analyze the properties of

light Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...

or optical materials. They include: *

Interferometer Interferometry is a technique which uses the '' interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber opt ...

for measuring the

interference Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extra ...

properties of light waves *

Photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ...

for measuring light intensity *

Polarimeter A polarimeter is a scientific instrument used to measure optical rotation: the angle of rotation caused by passing linearly polarized light through an Optical activity, optically active substance. Some chemical substances are optically active, ...

for measuring dispersion or rotation of polarized light * Reflectometer for measuring the

reflectivity The reflectance of the surface of a material is its effectiveness in Reflection (physics), reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the respon ...

of a surface or object *

Refractometer A refractometer is a laboratory or field device for the measurement of an Refractive index, index of refraction (refractometry). The index of refraction is calculated from the observed refraction angle using Snell's law. For mixtures, the index ...

for measuring

refractive index In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refrac ...

of various materials *

Spectrometer A spectrometer () is a scientific instrument used to separate and measure Spectrum, spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomeno ...

monochromator A monochromator is an optics, optical device that transmits a mechanically selectable narrow band of wavelengths of light or other radiation chosen from a wider range of wavelengths available at the input. The name is . Uses A device that can ...

for generating or measuring a portion of the

optical spectrum The visible spectrum is the band of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' (or simply light). The optical spectrum is sometimes consider ...

, for the purpose of chemical or material analysis * Autocollimator which is used to measure angular deflections * Vertometer which is used to determine refractive power of lenses such as glasses, contact lenses and magnifier lens DNA sequencers can be considered optical instruments, as they analyse the color and intensity of the light emitted by a fluorochrome attached to a specific nucleotide of a DNA strand. Surface plasmon resonance-based instruments use refractometry to measure and analyze biomolecular interactions.

Other types

Magic lantern The magic lantern, also known by its Latin name , is an early type of image projector that uses pictures—paintings, prints, or photographs—on transparent plates (usually made of glass), one or more lens (optics), lenses, and a light source. ...

* Polarization controller

References

External links

* * {{Authority control Instruments

Image enhancement

Analysis

Other types

See also

References

External links