Untitled Quiz

A thin, transparent fiber with a core surrounded by cladding. Both core and cladding are usually made of silica glass, but the core has a slightly higher refractive index.

The principle allowing light to travel through an optical fiber. Light reflects off the core-cladding boundary.

An optical fiber with a sudden change in refractive index between the core and the cladding.

The spreading of a light pulse as it travels down fiber. It limits the amount of information the fiber can carry.

Light pulse spreading caused by different modes of light traveling at slightly different speeds in the fiber.

A device used to boost the light signal in optical fiber communication.

Converts light signal into an electrical signal.

Devices that transform the electrical signal into a form understandable by humans (e.g., screen display).

The angle of incidence at which light entering a medium with a lower refractive index is refracted along the boundary between the two media.

The maximum angle of incidence for an incoming light ray into an optical fiber to be guided along the fiber.

A measure of light-gathering capability of an optical fiber; it represents the sine of the maximum angle at which light can enter the fiber and still be guided.

The ratio of the number of electron-hole pairs generated to the number of incident photons.

The ratio of the photocurrent generated in a photodetector to the incident optical power.

The refractive index of the central part of an optical fiber (core).

The refractive index of the outer layer (cladding) of an optical fiber.

A property of light waves where the waves have a constant phase relationship, resulting in a stable and predictable wave pattern.

Describes the correlation of light waves at the same point in space but at different times. Essentially, how consistent the wave's frequency is over time.

Describes the correlation of light waves at different points in space at the same time. This means the waves have a constant phase difference across space.

Light that lacks coherence. The waves have random phases, leading to a chaotic wave pattern.

The process where an excited atom randomly releases a photon and transitions to a lower energy level.

Einstein predicted a second emission process called stimulated emission, where an incident photon can trigger another excited atom to release a photon with the same properties.

The process where an excited atom releases a photon when stimulated by an incoming photon with matching energy. Both photons have the same properties.

A state where the energy distribution of a system is stable and unchanging. Atoms are neither gaining nor losing energy on average.

The minimum angle of incidence at which light will be totally internally reflected at the core-cladding interface of an optical fiber. This angle ensures the light stays confined within the core.

A type of signal distortion in multimode optical fibers. Light travelling along different paths (modes) within the core travels at different speeds, causing the signal to spread and weaken.

An optical fiber designed to only support the fundamental mode (the lowest order mode), eliminating intermodal dispersion. This allows signals to travel longer distances without significant distortion.

A semiconductor device that emits light when an electric current is passed through it. The emitted light is related to the energy gap of the semiconductor material.

Direct bandgap semiconductors directly emit light when electrons transition from the conduction band to the valence band. Indirect bandgap materials require the assistance of phonons (vibrations) for light emission.

A device that emits coherent, high-intensity light when stimulated by an electric current. Laser light is monochromatic, highly directional and highly focused.

A process where an excited atom emits a photon when stimulated by an incoming photon of the same energy, resulting in two identical photons.

A condition where more atoms are in an excited state than in the ground state.

The process of creating population inversion in a laser medium.

A device that amplifies light through stimulated emission of radiation, resulting in a coherent and monochromatic beam.

The maximum distance over which two points in a wave can interfere.

Helium atoms are excited by an electrical discharge and transfer energy to neon atoms, creating population inversion in neon and leading to laser action.

A three-dimensional image recorded by interference of light waves.

High-power lasers are used to write data by burning tiny pits on a medium, while low-power lasers read data by detecting reflected light.

Mathematical coefficients representing the rates of spontaneous emission (A), stimulated emission (B), and absorption (B) processes in an atomic system.

A non-equilibrium state in an atomic system where the population of atoms in a higher energy level exceeds the population in a lower energy level.

Population inversion occurs when an external energy source pumps atoms to a higher energy level, resulting in more excited atoms than ground state atoms.

A material that can be excited to achieve population inversion and amplify light, triggering laser action.

Stimulated emission amplifies light by triggering the release of more coherent photons with the same properties, leading to a high intensity laser beam.

Population inversion ensures that stimulated emission dominates over absorption, leading to light amplification and laser action.

Atoms are excited in lasers by external energy sources called pumps, which promote atoms from the lower energy level to the upper energy level, creating population inversion.