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Dic Microscopy: Differential Interference Contrast (DIC) optics can be installed on virtually any transmitted, reflected. Or inverted light field microscope, including devices with specially designed condenser and objective primers and polarizing filters.

All major microscope manufacturers produce DIC tools for their research-grade microscopes. Often assembling them in matching kits that contain all the necessary hardware and optics. In a typical setup, a differential contrast microscope contains the polarizing elements commonly. Found in polarizing microscopes, plus two specially designed birefringent prisms.

These optical beam splitters (and beam combiners) are also known as Wollaston or Nomarsky prisms. These are used to project cut-wavelength interpolation patterns onto the front focal plane of the condenser and the back focal plane of the objective.

Differential Interference Microscope Alignment Alignment

Before attempting to set up the microscope for differential interference observations. Check the device to see if it has all the necessary components and is free of lint, dust, and debris. Condenser and lens elements that contain stress characteristics can degrade image quality in the DIC. And contaminate dirty lens surfaces, scratches, and foreign objects in the optical path.

Proper microscope calibration is essential for best results and to create images that display virtual 3D effects and shadow effects. Many of the steps described in the following procedure are only required during the initial calibration of the DIC microscope. And do not need to be repeated during routine observations. Additional steps must be taken each time a microscope is used for a DIC examination.

Preliminary Microscope Inspection

Carefully inspect the microscope to ensure all necessary DIC components are installed or available and ready to use when needed. Remove the condenser, remove the turret and check the condition of the Nomarsky or Wollaston prism. The surfaces of these composite prisms must be clean and free of dust and debris. Because they are mounted on the condenser turret, DIC condenser prisms are rarely contaminated with fingerprints.

Although dust Dic Microscopy and lint can easily get into the turret and settle on one of the flat quartz surfaces. Use a rubber balloon to wipe the contaminated surface of the prism to remove loose fibers and debris. And/or gently wipe the surface with lens tissue or a soft cotton ball. Be careful not to scratch the surface.

Do the same with the objective prism condenser and outer lens, microscope eyepiece, and field lens in the field aperture port on the microscope base. After making sure critical parts are clean, reassemble the microscope, install the polarizer and analyzer, and align the Köhler optical illumination system.

Install the polarizer and analyzer:

After disassembling the microscope (without the condenser, DIC prism, and at least one lens), install the polarizer and analyzer in the corresponding positions below the condenser and above the lens, respectively. Similar to a polarizing microscope, the polarizer.

And analyzer is positioned so that their transmission azimuths intersect at an angle of 90 degrees (vertical). Polarizers placed between the light source and the condenser are traditionally oriented from left to right. Looking east or west or under the microscope. In some cases, the positions of the polarizers and analyzers are predetermined by their fixed positions on the mounting frame. And these components are only inserted into the microscope light path in a single orientation.

Usually, a pointer at the bottom of the polarizer indicates the direction of transmission, but some microscopes are equipped with rotational polarity in degrees. The analyzer can also be rotated with a scale knob and/or have a transmit signal. axis.

Checking the objective’s back aperture: After Koehler sets up the microscope illumination, set up the polarizer and analyzer. And use a phase telescope or Bertrand lens to check the objective’s back focal plane (observation function). If the polarizer and analyzer are positioned correctly and the microscope is perfectly aligned. A black sweat cross will appear at the objective aperture.

The arms of the extrusion Dic Microscopy:

The arms of the extrusion cross should be vertical and horizontal, with a small amount of visible light in the four corners of the opening. Points of light on the cross or in the aridest areas that affect the integrity of the crushed cross are a sign of visual fatigue.

Also, dust and soft particles near the focal plane of the aperture condenser (condenser or lens) appear brighter when viewed at the rear aperture of the lens. If there is a bifurcation, check the objective or other stress-free lens first to make sure the condenser lens system is worn. Remove any debris from the lens or condenser surface and replace worn optics (if possible) before proceeding to the next step.

Objective Prism DIC Alignment Dic Microscopy:

Install the objective prism Dic Microscopy by inserting the constrained prism into the slider or mounting base (for systems using the enormous polarization slowdown. Once the prism is in place, examine the back focal plane of the objective with a phase telescope or Bertrand lens.

The field of view should now look very bright but unusually dark, with a dark interference fringe running the full diameter of the aperture at a 45-degree v angle along the slice axis. Depending on whether the microscope is upright or inverted, the interference edge passes through the objective Dic Microscopy. Backstop in a northeast-southwest direction.


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