Differential interference contrast ( DIC ) microscopy , also known as Nomarski interference contrast ( NIC ) or Nomarski microscopy , is an optical microscopy technique used to enhance the contrast in unstained, transparent samples . DIC works on the principle of interferometry to gain information about the optical path length of the sample, to see otherwise invisible features. A relatively complex optical system produces an image with the object appearing black to white on a grey background. This image is similar to that obtained by phase contrast microscopy but without the bright diffraction halo. The technique was invented by Francis Hughes Smith. The "Smith DIK" was produced by Ernst Leitz Wetzlar in Germany and was difficult to manufacture. DIC was then developed further by Polish physicist Georges Nomarski in 1952.
34-587: (Redirected from NICs ) [REDACTED] Look up NIC in Wiktionary, the free dictionary. NIC may refer to: Banking and insurance companies [ edit ] National Insurance Corporation , Uganda NIC Bank , an erstwhile commercial bank in Kenya Politics, government and economics [ edit ] National Ice Center , an agency that provides worldwide navigational ice analyses for
68-690: A committee chaired by the Prime Minister of Pakistan regarding the Federally Administered Tribal Areas National Indigenous Council , an advisory body to the Australian Government from late 2004 to early 2008 National Informatics Centre , Government of India National Infrastructure Commission , a UK government body advising on large-scale infrastructure projects National Innovation Council (Philippines) ,
102-424: A committee chaired by the Prime Minister of Pakistan regarding the Federally Administered Tribal Areas National Indigenous Council , an advisory body to the Australian Government from late 2004 to early 2008 National Informatics Centre , Government of India National Infrastructure Commission , a UK government body advising on large-scale infrastructure projects National Innovation Council (Philippines) ,
136-452: A community college located in Coeur d'Alene, Idaho North Island College , a community college complex on the northern half of Vancouver Island, Canada North American Interfraternity Conference , an association of collegiate men's fraternities formally organized in 1910 Nursing Interventions Classification , a classification system for nursing See also [ edit ] Nic ,
170-400: A community college located in Coeur d'Alene, Idaho North Island College , a community college complex on the northern half of Vancouver Island, Canada North American Interfraternity Conference , an association of collegiate men's fraternities formally organized in 1910 Nursing Interventions Classification , a classification system for nursing See also [ edit ] Nic ,
204-552: A computer to communicate over a computer network New Internet Computer , former inexpensive Linux-based network computer Science and medicine [ edit ] A brand name for the drug lorazepam Nomarski interference contrast , a technique in microscopy Other topics [ edit ] "NIC", a song by Nines (rapper) National identity card (Sri Lanka) , an identity document in Sri Lanka Nagoya International Center ,
238-457: A computer to communicate over a computer network New Internet Computer , former inexpensive Linux-based network computer Science and medicine [ edit ] A brand name for the drug lorazepam Nomarski interference contrast , a technique in microscopy Other topics [ edit ] "NIC", a song by Nines (rapper) National identity card (Sri Lanka) , an identity document in Sri Lanka Nagoya International Center ,
272-493: A given name Nick (disambiguation) Nix (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title NIC . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=NIC&oldid=1251282472 " Category : Disambiguation pages Hidden categories: Short description
306-493: A given name Nick (disambiguation) Nix (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title NIC . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=NIC&oldid=1251282472 " Category : Disambiguation pages Hidden categories: Short description
340-673: A non-profit organization based in Nakamura-ku, Nagoya, Japan National Ice Centre , an ice and music arena in Nottingham, England New In Chess , a chess magazine issued eight times a year NIC Zuidlaren , an international horse riding competition in Zuidlaren, Netherlands The IATA airport code for Nicosia International Airport , an abandoned airport near Nicosia in Cyprus North Idaho College ,
374-417: A non-profit organization based in Nakamura-ku, Nagoya, Japan National Ice Centre , an ice and music arena in Nottingham, England New In Chess , a chess magazine issued eight times a year NIC Zuidlaren , an international horse riding competition in Zuidlaren, Netherlands The IATA airport code for Nicosia International Airport , an abandoned airport near Nicosia in Cyprus North Idaho College ,
SECTION 10
#1732772027261408-445: A topographically accurate image. 1. Unpolarised light enters the microscope and is polarised at 45°. 2. The polarised light enters the first Nomarski-modified Wollaston prism and is separated into two rays polarised at 90° to each other, the sampling and reference rays. 3. The two rays are focused by the condenser for passage through the sample. These two rays are focused so they will pass through two adjacent points in
442-550: Is different from Wikidata All article disambiguation pages All disambiguation pages NIC [REDACTED] Look up NIC in Wiktionary, the free dictionary. NIC may refer to: Banking and insurance companies [ edit ] National Insurance Corporation , Uganda NIC Bank , an erstwhile commercial bank in Kenya Politics, government and economics [ edit ] National Ice Center , an agency that provides worldwide navigational ice analyses for
476-447: Is different from Wikidata All article disambiguation pages All disambiguation pages Nomarski interference contrast DIC works by separating a polarized light source into two orthogonally polarized mutually coherent parts which are spatially displaced (sheared) at the sample plane, and recombined before observation. The interference of the two parts at recombination is sensitive to their optical path difference (i.e.
510-468: Is due to the similarity of refractive index of most samples and the media they are in: for example, a cell in water only has a refractive index difference of around 0.05. This small phase difference is important for the correct function of DIC, since if the phase difference at the joint between two substances is too large then the phase difference could reach 180° (half a wavelength), resulting in complete destructive interference and an anomalous dark region; if
544-441: Is used for imaging live and unstained biological samples, such as a smear from a tissue culture or individual water borne single-celled organisms. Owing to the maximally spatially incoherent illumination the theoretical resolution approaches the theoretical maximum coverage dictated by Ewald's sphere . This is an improvement on methods that require a higher degree of coherence like phase contrast . One non-biological area where DIC
578-400: Is used is in the analysis of planar silicon semiconductor processing. The thin (typically 100–1000 nm) films in silicon processing are often mostly transparent to visible light (e.g., silicon dioxide, silicon nitride and polycrystalline silicon), and defects in them or contamination lying on top of them become more visible. This also enables the determination of whether a feature is a pit in
612-704: The ISO 639-2 three-letter language code NIC Inc. (eGov.com), an information service provider for federal and state government in the United States Technology [ edit ] Negative impedance converter , configuration of an operational amplifier which acts as a negative load Network information center , formerly InterNIC, part of the Internet's Domain Name System (DNS) Network interface controller , electronic hardware that enables
646-462: The ISO 639-2 three-letter language code NIC Inc. (eGov.com), an information service provider for federal and state government in the United States Technology [ edit ] Negative impedance converter , configuration of an operational amplifier which acts as a negative load Network information center , formerly InterNIC, part of the Internet's Domain Name System (DNS) Network interface controller , electronic hardware that enables
680-602: The Philippine government's highest policy-making body for national innovation development National Institute of Corrections , a division of the United States Department of Justice National Insurance Contributions, UK contributions towards state benefits National Integration Council of India, to combat the problems of Communalism, casteism and Regionalism National Intelligence Council , center for midterm and long-term strategic thinking within
714-466: The Philippine government's highest policy-making body for national innovation development National Institute of Corrections , a division of the United States Department of Justice National Insurance Contributions, UK contributions towards state benefits National Integration Council of India, to combat the problems of Communalism, casteism and Regionalism National Intelligence Council , center for midterm and long-term strategic thinking within
SECTION 20
#1732772027261748-483: The United States intelligence community National Irrigation Commission , Jamaica agricultural irrigation government commission Newly industrialized country , a socio-economic classification status used by political scientists Nicaragua , the ISO 3166-1 three-letter country code NIC Argentina , Network Information Center, an office of Argentina's Ministry of Foreign Affairs Niger–Congo languages ,
782-420: The United States intelligence community National Irrigation Commission , Jamaica agricultural irrigation government commission Newly industrialized country , a socio-economic classification status used by political scientists Nicaragua , the ISO 3166-1 three-letter country code NIC Argentina , Network Information Center, an office of Argentina's Ministry of Foreign Affairs Niger–Congo languages ,
816-491: The United States military and government National Incubation Center , Ignite - National Technology Fund, Ministry of IT & Telecom, Government of Pakistan National Iranian Congress , a political organization founded in U.S.-based for a free and democratic Iranian Natal Indian Congress , a political party in South Africa formed by Mohandas Karamchand Gandhi National Implementation Committee on FATA Reforms ,
850-430: The United States military and government National Incubation Center , Ignite - National Technology Fund, Ministry of IT & Telecom, Government of Pakistan National Iranian Congress , a political organization founded in U.S.-based for a free and democratic Iranian Natal Indian Congress , a political party in South Africa formed by Mohandas Karamchand Gandhi National Implementation Committee on FATA Reforms ,
884-456: The appearance of a three-dimensional object under very oblique illumination, causing strong light and dark shadows on the corresponding faces. The direction of apparent illumination is defined by the orientation of the Wollaston prisms. As explained above, the image is generated from two identical bright field images being overlaid slightly offset from each other (typically around 0.2 μm), and
918-407: The phase difference reached 360° (a full wavelength), it would produce complete constructive interference, creating an anomalous bright region. The image can be approximated (neglecting refraction and absorption due to the sample and the resolution limit of beam separation) as the differential of optical path length with respect to position across the sample along the shear, and so the differential of
952-430: The product of refractive index and geometric path length). Adding an adjustable offset phase determining the interference at zero optical path difference in the sample, the contrast is proportional to the path length gradient along the shear direction, giving the appearance of a three-dimensional physical relief corresponding to the variation of optical density of the sample, emphasising lines and edges though not providing
986-407: The refractive index (optical density) of the sample. The contrast can be adjusted using the offset phase, either by translating the objective Nomarski prism, or by a lambda/4 waveplate between polarizer and the condenser Normarski prism (De-Senarmont Compensation). The resulting contrast is going from dark-field for zero phase offset (intensity proportional to the square of the shear differential), to
1020-400: The sample, around 0.2 μm apart. 4. The rays travel through adjacent areas of the sample, separated by the shear. The separation is normally similar to the resolution of the microscope. They will experience different optical path lengths where the areas differ in refractive index or thickness. This causes a change in phase of one ray relative to the other due to the delay experienced by
1054-416: The subsequent interference due to phase difference converting changes in phase (and so optical path length) to a visible change in darkness. This interference may be either constructive or destructive, giving rise to the characteristic appearance of three dimensions. The typical phase difference giving rise to the interference is very small, very rarely being larger than 90° (a quarter of the wavelength). This
NIC - Misplaced Pages Continue
1088-465: The substrate material or a blob of foreign material on top. Etched crystalline features gain a particularly striking appearance under DIC. Image quality, when used under suitable conditions, is outstanding in resolution. However analysis of DIC images must always take into account the orientation of the Wollaston prisms and the apparent lighting direction, as features parallel to this will not be visible. This is, however, easily overcome by simply rotating
1122-401: The typical relief seen for phase of ~5–90 degrees, to optical staining at 360 degrees, where the extinguished wavelength shifts with the phase differential. When sequentially shifted images are collated, the phase-shift introduced by the object can be decoupled from unwanted non-interferometric artifacts, which typically results in an improvement in contrast, especially in turbid samples. DIC
1156-403: The wave in the more optically dense material. 5. The rays travel through the objective lens and are focused for the second Nomarski-modified Wollaston prism. 6. The second prism recombines the two rays into one polarised at 135°. The combination of the rays leads to interference , brightening or darkening the image at that point according to the optical path difference. The image has
#260739