Introduction
Light is a type of energy that is used in a variety of applications from the production of multiple materials to its useful presence in scientific and industrial research and studies. Its application has found specific use in light microscopy. Light microscopy involves the use of light to observe and view objects in scientific and industrial research and studies. This light is used to ascertain the shape and size of particles or materials as well as their physical and chemical properties, hence, it is referred to as optical microscopy or optically physical study. This can be done with the assistance of a microscope that relies on the ability of the light to interact with materials or matter. Interaction with the materials or matter causes the light to bend, reflect, and focus on the target material. These processes are known as refraction, reflection and total internal reflection respectively. This essay therefore intends to discuss these three processes, namely, refraction, reflection, and total internal reflection and their applications in light microscopy.
Refraction
Light refraction can be described as a process in which light deviates from a straight line to its direction when passing through a medium from one material to another. It is the process of the light bending when it passes from a medium of one refractive index to a medium of a higher refractive index. Mediums of a high refractive index such as glass bend light more strongly than that in regular air. Therefore, it is essential to use materials of a different refractive index in order to create the most benefical optical system.
Reflection
When light reflects off an object, it changes direction and its angle of incidence is equal to its angle of reflection. In the case of objects such as mirrors, the light is reflected back at the same angle and with the same intensity as the angle and intensity that the light was shone on the object. Reflective optics utilizes this property of light by manipulating the direction or the angle of incidents with the utilization of curved reflective surfaces. This makes it possible for the reflected light to be focused into a concentrated beam or point of light. In microscopy, reflective optics are used to focus light onto the sample materials being observed.
Total Internal Reflection
Total internal reflection occurs when incoming light is reflected back 100% into the same medium from which the light originates. This situation occurs when the angle of incidence of the incoming light is greater than the angle of critical refraction, thus the light is unable to pass through the boundary and is instead, totally internally reflected. In microscopy, total internal reflections are used to analyze material samples that are in a near boundary region. Since total internal reflection occurs at certain angles, it allows scientists and researchers to focus on the shape and type of sample material as well as its physical or chemical properties.
Applications in Light Microscopy
The application of refraction, reflection and total internal reflection in light microscopy is crucial in the study and analysis of material samples. Refraction and reflection allow the light to focus on the sample material and micron-levels of accuracy. For example, the use of lenses of different refractive index help to focus light onto sample material and to determine the physical and chemical properties of the sample material. In addition, reflection allows for the use of curved reflective surfaces to focus a concentrated beam of light towards the sample material pointing towards different directions. On the other hand, total internal reflection allows for the examination of material sample in near boundary regions which is an extremely helpful tool in particular light microscopy studies.
Conclusion
In conclusion, the processes of light refraction, reflection and total internal reflection are all of great importance in the field of microscopy, since they are all involved in the process of light interaction with objects and materials. They affect the shape, size and the physical and chemical properties of the materials under study. The use of different lenses, curved reflective surfaces and materials of different refractive index makes these processes possible in order to allow scientists, researchers and other workers in the field to obtain accurate information in their studies. Therefore, it is important to understand the use and applications of these processes in light microscopy in order to obtain better results.
