Clive W. Humphris

**OPTICS: Light Propagation. **

Understanding that propagation of light is in straight lines is fundamental to the study of opto-electronics and is especially applicable to the principles of fibre optics. This example clearly shows that the path is straight, but can be blocked.

Light from the source is propagated in every direction and is only directed through reflection. It cannot be cut off, even if a shield is placed in its path as the obstruction just absorbs the energy.

A light ray is an imaginary line which is used to represent the path along which the energy carried by the light wave travels. A beam of light is made up of lots of rays which can be spread out or converged onto a single point. As the energy is directed to a pinpoint it becomes more intense i.e. the light becomes brighter, conversely the light appears dimmed, as its directed over a larger area.

Light waves are humanly visible electromagnetic radiation, forming just a very small part of the full electromagnetic spectrum that ranges from audio frequencies through, radio, infrared, ultraviolet to gamma rays. When all the frequencies in the visible spectrum reach the eye we see white light, otherwise we see a colour.

- Table of Contents
- Interactive eTextbooks
- Basic Electronics
- Conductor And Insulator
- Resistor Value Test
- Simple Dc Circuits
- Types Of Switching
- Variable Voltages
- Ohm's Law
- DC Voltage
- DC Current
- Series and Parallel Resistors
- AC Measurement
- AC Voltage and Current
- AC Theory
- RCL Series
- RCL Parallel
- Capacitance
- Capacitors
- Inductance
- Inductors
- Impedance
- Tuned Circuits
- Attenuators
- Passive Filters
- Active Filters
- Oscillators
- Circuit Theorems
- Complex Numbers
- DC Power
- AC Power
- Silicon Controlled Rectifier
- Power Supply
- Voltage Regulation
- Magnetism
- Electrical Machines
- Transformers
- Three Phase Systems
- Energy Transfer and Cost
- Atomic Structures
- Diode Theory
- Diode Applications
- Transistor Theory
- Bipolar Transistors
- Transistor Configurations
- Active Transistor Circuits
- Field Effect Transistors
- Basic Operational Amplifier
- Op-Amp Theory
- Op-Amp Applications
- Sum and Difference Amplifiers
- Analogue Multi-Meter
- Measurement
- Component Testing
- Area
- Surface Area and Symmetry
- Volume
- Compound Measures
- Geometry
- Motion
- Machines
- Optics
- Number Systems
- Number Conversion
- Number Types
- Roots
- Angles and Parallels
- Triangle Ratios
- Triangle Angles
- Percentages
- Ratios
- Fractions
- Vectors
- Circle Angles
- Laws
- Algebra 0
- Algebra 1
- Algebra 2
- Mathematical Rules
- Powers and Indices
- Simplifying
- Linear Equations
- Graphing
- Slope and Translation
- Curves and Angle Conversion