Optical microcavity

Moreover, nonlinear effects are enhanced by orders of magnitude due to the strong light confinement, leading to the generation of microresonator frequency combs, low-power parametric processes such as down-conversion, second-harmonic generation, four-wave mixing and optical parametric oscillation.

[6] Microcavities have many applications, frequently at present in optoelectronics, where vertical cavity surface emitting lasers VCSEL are probably the best known.

[7] For a microcavity supporting a single-mode or a few standing-wave modes, the thickness of the spacer layer determines the so-called "cavity-mode", which is the one wavelength that can be transmitted and will be formed as a standing wave inside the resonator.

Depending on the type and quality of the mirrors, a so-called stop-band will form in the transmission spectrum of the microcavity, a long range of wavelengths, that is reflected and a single one being transmitted (usually in the centre).

[10] This also leads to an ultrahigh quality factor, meaning that light travels around the circumference many million times before decaying into the surroundings.