Presenter : Khizra Samad
optical microscope, often referred to as the
is a type of microscope which uses visible light
and a system of lenses to magnify images of small
microscopes are the oldest design of
microscope and were possibly designed in 17th
optical microscopes can be very simple, but
there are many complex designs which aim to
improve resolution and sample contrast.
Historically optical microscopes were easy to develop
and are popular because they use visible light so that
samples may be directly observed by eye.
The image from an optical microscope can be captured
by normal light-sensitive cameras to generate a
Originally images were captured by photographic film
Modern developments in CMOS and charge-coupled
device (CCD) cameras allow the capture of digital
Purely digital microscopes are now available which use
CCD camera to examine a sample, showing the
resulting image directly on a computer screen without
the need for eyepieces.
A modern microscope with a mercury bulb for
fluorescence microscopy. The microscope has a
digital camera, and is attached to a computer.
An optical microscope consists of the following two major
Creating a Magnified Image of a Specimen (observation
Illuminating a Specimen
Creating a Magnified Image of a
The function to create a magnified image of
a specimen consists of three basic functions :
Obtaining a clear, sharp image
Changing a magnification
Bringing into focus".
An optical system for implementing these
functions is referred to as an observation optical
Illuminating a Specimen
function to illuminate a specimen consists of
three basic functions :
1. supplying light
2. collecting light
3. changing light intensity
An optical system for implementing these functions is
referred to as an illumination optical system.
illumination optical system effectively collects
light emitted from the light source and leads the
light to a specimen to illuminate it.
Extensively used in microelectronics, nanophysics,
biotechnology, pharmaceutics research, mineralogy
Used for medical diagnosis, when dealing with tissues, or
in smear tests on free cells or tissue fragments.
In industrial use, binocular microscopes are common.
In certain applications, long-working-distance or longfocus microscopes[are beneficial. An item may need to
be examined behind a window, or industrial subjects
may be a hazard to the objective. Such optics resemble
telescopes with close-focus capabilities