Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Downconversion and phase matching

Description

This lecture covers topics such as transverse Laplacian, paraxial approximation, nonlinear propagation equations, weak conversion regime, impact of phase matching on second harmonic generation, summary on OPA and OPO, power exchange in an amplifier, Manley Rowe Relations, three wave mixing, squeezing, and noncollinear phase matching in SPDC.

Official source

Related concepts (32)

Nonlinear optics

Nonlinear optics (NLO) is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization density P responds non-linearly to the electric field E of the light. The non-linearity is typically observed only at very high light intensities (when the electric field of the light is >108 V/m and thus comparable to the atomic electric field of ~1011 V/m) such as those provided by lasers. Above the Schwinger limit, the vacuum itself is expected to become nonlinear.

Second-harmonic generation

Second-harmonic generation (SHG, also called frequency doubling) is a nonlinear optical process in which two photons with the same frequency interact with a nonlinear material, are "combined", and generate a new photon with twice the energy of the initial photons (equivalently, twice the frequency and half the wavelength), that conserves the coherence of the excitation. It is a special case of sum-frequency generation (2 photons), and more generally of harmonic generation.

Amplifier

An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input.

Valve amplifier

A valve amplifier or tube amplifier is a type of electronic amplifier that uses vacuum tubes to increase the amplitude or power of a signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers in the 1960s and 1970s. Valve amplifiers can be used for applications such as guitar amplifiers, satellite transponders such as DirecTV and GPS, high quality stereo amplifiers, military applications (such as radar) and very high power radio and UHF television transmitters.

Guitar amplifier

A guitar amplifier (or amp) is an electronic device or system that strengthens the electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which are typically housed in a wooden cabinet. A guitar amplifier may be a standalone wood or metal cabinet that contains only the power amplifier (and preamplifier) circuits, requiring the use of a separate speaker cabinet–or it may be a "combo" amplifier, which contains both the amplifier and one or more speakers in a wooden cabinet.

Related lectures (38)

Difference Frequency Generation: Energy Conservation and Amplification

Explores difference frequency generation, energy conservation, and signal amplification in optics.

MIR Spectral Domain and Femtosecond Amplifiers

Covers the MIR spectral domain, femtosecond amplifiers, and nonlinear optics, exploring experimental setups and applications like pump-probe spectroscopy.

Nonlinear wave propagation and paraxial approximation

Explores nonlinear wave propagation, optical harmonics generation, and paraxial approximation concepts.

General Formalism for Nonlinear Susceptibility

Covers the general formalism for nonlinear susceptibility in optical response and wave propagation.

Transistor Bipolaire: Summary and Examples MOOC: Electronics II