Glossary
Q
- quadrocular tube
- An observation tube which typically permits viewing through two eyepieces and up to two cameras (4 total ports).
- See also: observation tube, monocular tube, binocular tube, trinocular tube, eyepiece
- quantitative phase contrast microscopy
- see quantitative phase microscopy
- quantitative phase imaging
- see quantitative phase microscopy
- quantitative phase microscopy (QPM)
- An family of label-free, coherent imaging techniques for determining the absolute phase shift experienced by light transmitted through an object (must have high degree of optical transparency). Methods such as optical diffraction tomography (ODT) can be used to determine the 3D refractive index distribution of an object.
- Synonyms: quantitative phase imaging, quantitative phase contrast microscopy
- See also: optical diffraction tomography
- quantum
- In optics, this typically refers to the minimum amount of light (i.e. a photon) that can be discretized.
- quantum efficiency (QE)
- A measure of the ability for a detector to convert incident photons into detected photoelectrons, without regard to sources of noise. This value can vary greatly with the wavelength of light.
- See also: camera, photodiode
- quantum yield
- The measure of a ratio between the number of photons absorbed and emitted by a fluorophore. The intrinsic brightness of a fluorophore is often expressed as the product of its quantum yield and extinction coefficient.
- See also: brightness (fluorophore), extinction coefficient, fluorescence, fluorophore
- quarter-wave compensator
- see half-wave plate
- quarter-wave plate
- Typically a birefringent material used to introduce a quarter-wave phase difference between the ordinary and extraordinary rays. The axis corresponding to the lowest refractive index is the fast axis, the orthogonal axis is the slow axis. It's commonly used to convert linearly polarized light to circularly polarized light, or vice versa.
- Synonyms: quarter-wave compensator
- See also: polarized light microscopy, polarized light, birefringence, compensator, half-wave compensator
- quartz-wedge compensator
- A compensator with a variable range of retardation values (typically between 500 and 2000 nanometers). This is typically used to qualitatively assess properties of birefringent samples, such as their optic sign.
- See also: polarized light microscopy, polarized light, birefringence, compensator
