Lecture 3 & 4-- Wave Properties & Light Microscopy -- BMEN 311

Lecture 3 -- Wave Properties & Light Microscopy -- BMEN 311

Biomedical Imaging Techniques are Founded on

interactions between waves and sound

Light Microscopy Characteristics

• Resolution max = 200 nm

• Magnification Limit = x2000

• Light can refract, reflect, or absorb

Components of Light Microscopy

• Light Source

• Condenser

• Objective Lens

• Eyepiece (Ocular Lens)

Objective Lens

• collects and refracts light

• magnifies image for eyepiece to view

Image Formation

• image is magnified, flipped, and blurred

• PSF causes blurred due to light passing thru aperture which causes diffraction

Diffraction Limit

• min distance between 2 points that lets them be seen as distinct

• Depends on: wavelength and Numerical Aperture of Objective Lens

Condenser

collects and focuses light from illuminator onto specimen unders tage

Iris Diaphragm

• controls how much light reaches specimen

• varies size of diaphragm opening

Geometrical or Spherical Aberration

blurring or distortion of image due to light rays from periphery of lens focusing at different points than those form center

Chromatic Aberration

blurring or color fringing of images due to wavelengths focusing at different points