Refraction, Interference, and Optical Biosensors: Key Concepts in Light Behavior and Color Shifts

What is refraction?

The bending of light as it passes through two mediums

What causes refraction?

change in speed of light

Constructive interference

Light waves are "in phase," leading to a color being magnified

Destructive Interference

Light waves are "out of phase," leading to colors being diminished

How is thickness a parameter that can cause shifts in color?

changes the amount the light needs to travel in order to reflect and how the waves interfere with each other. Can either go through constructive or destructive interference.

How is changes to the material a parameter that can cause shifts in color?

Alters the index of refraction, causing the light to bend differently when hitting the film. This results in different colors or intensities of colors being shown.

How are the films pores a parameter that can cause shifts in color?

When filled can cause changes to the index of refraction because the light would then bend through other materials than the original film. Results in different colors or intensities being shown

Relationship between refraction and optical biosensors

Optical biosensors use principles of refraction in order to detect different molecules. This can be used to detect cancer causing genes

How can optical biosensors be used to detect cancer?

When the cancer causing gene is present the film would bind causing a change in the index of refraction

In the nail polish lab, what parameter was altered when the water was dropped onto the nail polish sample? How did this change cause the observed effect?

The thickness of the film was changed altering how the rays interacted, depending on the distance and how the light is interfered and refracted.

Imagine there is a crown glass, and we mix in another substance changing ita composition. This change causes the angle at which the light is refracted to decrease. Did the index of refraction of the glass go up or down?

The index of refraction went up because when the angle decreases the light slows down, causing the light to bend closer to the normal. This means that the angle inside of the material has become smaller making the glass have a smaller refractive index.

What causes the film of the bubble to look differently from different angles?

Constructive and destructive interference, and how the waves hit our eyes