Optical Communication Systems Quiz

The physical medium through which optical signals travel. Examples include optical fibers, air, and water.

A core of glass or plastic that carries the optical signal. It has a high refractive index, meaning light bends more when it enters it from the cladding.

A layer of glass or plastic surrounding the core. It has a lower refractive index than the core, causing light to be reflected back into the core.

The phenomenon where light travels through a medium (the core) and is reflected back into it at the boundary with another medium (the cladding).

The angle at which light strikes the boundary between the core and cladding. It must be greater than the critical angle for Total Internal Reflection to occur.

The minimum angle at which light must strike the boundary between the core and cladding for Total Internal Reflection to occur.

The ability of an optical fiber to carry multiple signals simultaneously. Each signal can be modulated at different frequencies.

A device that combines or separates multiple optical signals, allowing for efficient transmission over a single fiber.

The angle at which light enters a medium from a different medium, causing it to bend.

The angle at which light bends when passing from one medium to another.

The ratio of the speed of light in a vacuum to the speed of light in a medium.

The process of combining multiple signals onto a single transmission medium, like an optical fiber.

A device that separates multiple optical signals traveling on a single fiber, allowing each signal to be transmitted independently.

The change in refractive index between the core and cladding of an optical fiber, causing an abrupt change in the direction of light.

A type of optical fiber where the refractive index is uniform throughout the core and cladding.

A type of optical fiber where the refractive index changes gradually from the core to the cladding.

The probability of a system transitioning from one energy state to another due to interaction with electromagnetic radiation.

The process where an atom or molecule absorbs a photon and transitions to a higher energy level.

The process where an atom or molecule in an excited state emits a photon and transitions to a lower energy level.

The process where an atom or molecule in an excited state emits a photon when stimulated by an external electromagnetic field.

The state of equilibrium where the rate of absorption equals the rate of emission in a system.

The probability that a system will be in a particular energy state at a given temperature.

A quantized energy packet that can be absorbed or emitted by atoms or molecules.

The energy difference between two electronic energy levels in an atom or molecule.

Attenuation refers to the loss of signal strength as it travels through an optical fiber. It's expressed as a loss in decibels per unit length.

Attenuation in optical fibers is primarily caused by two factors: absorption and scattering.

Absorption occurs when light energy is converted into heat by the fiber material. This happens when light interacts with molecules and dopants in the glass.

Scattering happens when light encounters imperfections or variations in density within the fiber material, causing light to be deflected in different directions.

Cladding surrounds the core of an optical fiber. It has a lower refractive index than the core, which helps to confine light within the core through total internal reflection.

The refractive index of a material is a measure of how much light bends when it passes from one medium to another. A higher refractive index means more bending.

Total internal reflection occurs when light traveling in a denser medium (the core) strikes the boundary with a less dense medium (the cladding) at an angle greater than the critical angle. This causes the light to be reflected back into the core.

The critical angle is the minimum angle of incidence at which total internal reflection will occur.

A state where an atom or molecule is in its lowest energy level, indicating it's the most stable state, and has its electrons in their ground state.

An unstable state where an atom or molecule is in a higher energy level than the ground state, with its electrons in excited orbitals.

The process where an excited atom or molecule transitions back down to a lower energy level, often releasing energy as light or heat.

The energy difference between the excited and ground states, determining the wavelength of light emitted during relaxation.

The process where atoms absorb energy (like light) and transition to an excited state, promoting an electron to a higher energy orbital.

The phenomenon where light amplifies as it interacts with a material that possesses excited atoms, causing stimulated emission of more photons with the same energy and phase, leading to coherent light.

A device that uses stimulated emission to create intense, coherent beams of light.

A type of laser that uses a medium that can be excited by pumping energy into it, allowing it to reach a state with more excited atoms than ground-state atoms, which can then be stimulated to emit light.