Optical_Resonators Flashcards
What is an optical resonator?
An optical resonator is a device that confines and stores light at particular frequencies by guiding the propagation of light along a path that causes it to come back along itself.
What is a Fabry-Perot resonator?
A Fabry-Perot resonator is a simple one-dimensional resonator consisting of two parallel planar mirrors between which light is repeatedly reflected with little loss.
What is the free spectral range (FSR) in a Fabry-Perot resonator?
The free spectral range (FSR) is the spacing between adjacent resonance frequencies in a Fabry-Perot resonator.
What are longitudinal modes in an optical resonator?
Longitudinal modes are specific, discrete frequencies of light that can exist within an optical resonator, related to the propagation of light.
What are transverse resonator modes?
Transverse resonator modes are specific spatial beam shapes supported by the resonator, such as Gaussian, Hermite-Gaussian, or other beam profiles.
What is the significance of the resonance condition φ = q · 2π?
This condition ensures that the phase shift after a round trip in the resonator is a multiple of 2π, allowing the wave to reproduce itself and build up inside the resonator.
How does loss affect the resonance in an optical resonator?
Loss causes the magnitudes of the phasors in the resonator to decrease, leading to broader resonance linewidths and lower finesse.
What are the two principal sources of loss in optical resonators?
The two principal sources of loss are absorption and scattering in the medium, and imperfect reflection at the mirrors.
Why are spherical mirror resonators more stable than planar mirror resonators?
Spherical mirror resonators are less sensitive to misalignment because the curvature of the mirrors helps confine the light more effectively.
What is the stability criterion for a spherical mirror resonator?
The stability criterion is 0 < g1g2 < 1, where g1 = 1 - d/R1 and g2 = 1 - d/R2, with d being the mirror separation and R1, R2 the radii of curvature of the mirrors.
What happens when the stability condition of a resonator is not satisfied?
If the stability condition is not satisfied, the resonator is unstable, meaning it cannot confine a real beam of light, and the beam will eventually escape the resonator.
What is a symmetric confocal resonator?
A symmetric confocal resonator has equal mirror curvatures (R1 = R2) and a mirror separation equal to the focal length (d = R1 = R2), with the beam waist located at the center.
How does the beam waist position vary in a symmetric spherical mirror resonator?
In a symmetric resonator (R1 = R2), the beam waist is centered in the resonator, and its position depends on the mirror separation d and the radius of curvature R.
What is the relation between beam waist and the resonator parameters in a symmetric spherical mirror resonator?
The beam waist W0 is related to the resonator parameters by W0 = sqrt(λd/2π) * sqrt(2R/d - 1), where λ is the wavelength, d is the mirror separation, and R is the radius of curvature.
What are the g-parameters in a spherical mirror resonator?
The g-parameters are g1 = 1 - d/R1 and g2 = 1 - d/R2, where d is the distance between the mirrors, and R1 and R2 are the radii of curvature of the mirrors.
