What are Laguerre-Gaussian modes?
Laguerre-Gaussian modes The effect of the rotational mode number l, in addition to affecting the Laguerre polynomial, is mainly contained in the phase factor exp(−ilφ), in which the beam profile is advanced (or retarded) by l complete 2π phases in one rotation around the beam (in φ).
What is a Laguerre-Gaussian beam?
Laguerre-Gaussian beam can transfer orbital momentum to a trapped particle, inducing it to rotate around the optical axis. For this reason, Laguerre-Gaussian optical tweezers are also known as “optical vortices” [10-13].
What are Hermite Gaussian modes?
The electric field distributions of the Hermite–Gaussian modes are a system of functions which are mutually orthogonal. Arbitrary field distributions can be decomposed into Hermite–Gaussian functions, where the amplitude content of each one is determine by an overlap integral.
Are all lasers Gaussian?
In general, not all lasers are single mode and not all lasers are equipped with those kind of cavities (e.g., solid-state lasers). Therefore, not all laser beams are perfectly Gaussian.
What is beam quality M2?
The M2 factor of a laser beam limits the degree to which the beam can be focused for a given beam divergence angle, which is often limited by the numerical aperture of the focusing lens. Together with the optical power, the beam quality factor determines the brightness (more precisely, the radiance) of a laser beam.
How is Gaussian curvature calculated?
The Gaussian curvature of σ is K = κ1κ2, and its mean curvature is H = 1 2 (κ1 + κ2). To compute K and H, we use the first and second fundamental forms of the surface: Edu2 + 2F dudv + Gdv2 and Ldu2 + 2Mdudv + Ndv2.
What does Gaussian curvature show?
The Gaussian curvature is the product of the two principal curvatures Κ = κ1κ2. The sign of the Gaussian curvature can be used to characterise the surface. If both principal curvatures are of the same sign: κ1κ2 > 0, then the Gaussian curvature is positive and the surface is said to have an elliptic point.
Why are beams Gaussian?
Resonator Modes Gaussian modes are the lowest order modes of an optical resonator, set along the transverse direction. A stable resonator will have homogeneous optical media, and a flat or parabolic surface between the media. Hence, lasers in the fundamental transverse mode often emit beams close to Gaussian shape.
Is a Gaussian beam a plane wave?
Gaussian beam can describe both planewave-like behavior at near field and give spherical-wave-like at farfield. It is a highly versatile model for coherent optical beams (laser beam) that can be used in many calculation.
What is M2 factor?
How thin can lasers be?
The size of a conventional laser is dictated by the wavelength of the light it uses, and the distance between the reflective surfaces can’t be smaller than half the wavelength of the light–in the case of visible light, about 200 nanometers.