An optical instrument (or "optic" for short) is a device that processes light waves (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 particle, massless ...

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

microscope A microscope () is a 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 means being invisibl ...

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...

s, and

camera A camera is an optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), with a ...

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

electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from ...

. 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 and

camera obscura A camera obscura (; ) is a darkened room with a small hole or lens at one side through which an image is projected onto a wall or table opposite the hole. ''Camera obscura'' can also refer to analogous constructions such as a box or tent in ...

being very simple examples of such devices.

Analysis

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

light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 te ...

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 o ...

for measuring the interference 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 the angle of rotation caused by passing polarized light through an optically active substance.polarized light Polarization ( also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of t ...

* Reflectometer for measuring the

reflectivity The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electroni ...

of a surface or object * Refractometer for measuring

refractive index In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, o ...

of various materials *

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

or monochromator for generating or measuring a portion of the

optical spectrum The visible spectrum is the portion 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. A typical human eye will respond to wa ...

, 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 Refractometry is the analytical method of measuring substances' refractive index (one of their fundamental physical properties) in order to, for example, assess their composition or purity. A refractometer is the instrument used to measure refract ...

to measure and analyze biomolecular interactions.

Other types

* Polarization controller *

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

References

External links

* * {{Authority control

Instruments Instrument may refer to: Science and technology * Flight instruments, the devices used to measure the speed, altitude, and pertinent flight angles of various kinds of aircraft * Laboratory equipment, the measuring tools used in a scientific l ...

Image enhancement

Analysis

Other types

See also

References

External links