Chapter 4: Microscopy

a.k.a. spherical aberration -- results from a lens not being properly spherical.

Produce very high- quality images and allow for the addition of a variety of analytical components to the microscope.

The result of this division of light into at least two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, depending on the polarization of the light.

An angular measure of the lenss light- gathering ability and, ultimately, its resolving quality.

________ are used in forensic laboratories to analyze a wide variety of samples, including paint, particles, fractures, toolmarks, and gunshot residue.

The most important part of the microscope.

________ assist analysts in detecting materials of interest, like gunshot residue particles.

Contain several internal lenses that have different thicknesses and curvatures in a specific configuration unique to ________.

A translucent material that bends light in a known and predictable manner.

Located above the objectives, it can be manually slid into or out of the light path.

It is a device used to determine whether the light is plane polarized or not.

a French geologist, was born in Paris and became inspector-general of mines and director of the Geological Survey of France.

Employs a magnification system that exceeds the limits imposed by simple lenses.

Concentrates the light on the specimen with the condenser lens; this produces an intense lighting that highlights edges but may be uneven.

________ lack correction for flatness of field, but recently most manufacturers have started offering flat- field corrections for achromat objectives, called plan achromats.

The ________ is the platform where the specimen sits during viewing.

A ________ focuses a flat specimen on a microscope slide onto the lens, a rounded surface.

In ________, the electron beam passes through a specimen that has been very thinly sectioned and projects the beam onto a specially treated plate that transmits the image to a monitor.

The relative speed at which light moves through a material with respect to its speed in a vacuum.

Measures the wavelength of the emitted radiation using a tightly spaced crystal lattice.

The distance between the two points of focus on either side of the lens.

a single lens used to form an enlarged image of an object

Where magnification occurs in two stages and the total magnification is the product of the magnification of the first lens and the second lens

The distance from the lowest part of the objective to the upper edge of the eyepiece.

Used to obtain a bright, even field of view and improve image resolution

A control that allows more or less light into the lens system of the microscope

Sets the light rays parallel throughout the lens system, allowing them to evenly illuminate the specimen

Exploits optical properties of materials to discover details about the structure and composition of materials, and these lead to its identification and characterization

Demonstrate the same optical properties in all directions, such as gases, liquids, and certain glasses and crystals

The wavelengths being added and subtracted through interference; these colors are caused by the interference of the two rays of light split by the anisotropic material interfering destructively with each other

a chart of diameter, birefringence, and retardation

Detects elastically scattered electrons.

A used technique for elemental analysis and chemical composition determination, associated with electron microscopy.

The observer looks at the first image with a lens that produces an enlarged image called a _______.

the one that could be seen on the screen—that is, projected onto the screen.

a translucent material that bends light in a known and predictable manner.

the lens that the observer looks into when viewing an object microscopically.

where white light from the specimen is broken out into multiple colored images at various distances from the lens.

a rounded surface wherein a simple lens focuses a flat specimen on a microscope slide onto the lens.

Regular achromats lack correction for flatness of field, but recently most manufacturers have started offering flat-field corrections for achromat objectives, called _____.

occurs as light passes from one medium to another when there is a difference in the index of refraction between the two materials, and it is responsible for a variety of familiar phenomena such as the apparent distortion of objects partially submerged in water.

exploits optical properties of materials to discover details about the structure and composition of materials, and these lead to its identification and characterization.

a special filter used when the light passes through it, the only light that passes is that which vibrates in that “preferred” direction.

Long-lived emission.

This is where the emission stops when the excitations stops.

______ employs a particle beam of electrons focused on magnetic lenses. It does have a much higher resolving power and greater depth of field than light microscopes and can magnify a specimen hundred of thousands of times.