Optical Cross Section

The standard unit of measurement is displaystyle frac m 2 sr.

Optical cross section. The cross sections cm2molecule 1 can be incorporated directly into a line by line calculation as additive spectral values to the infinite resolution line absorption coefficients with proper wavenumber interpolation before the instrument function is applied. It is dependent on the geometry and the reflectivity at a particular wavelength of an object. Transition cross sections depend on the optical frequency or wavelength.

Optical cross section or ocs is a value which describes the maximum amount of optical flux reflected back to the source. Optical cross section or ocs is a value which describes the maximum amount of optical flux reflected back to the source. Optical cross sections corresponding to spectral lines of li na k ca sr ba tl cu ag cr mn fe co and ni emitted by an acetylene air flame have been determined.

It is dependent on the geometry and the reflectivity at a particular wavelength of an object. To excite φ 10 of molecules in an optically transparent solution the photon excitation density must be n ϕ σ 10 15 cm 2 cm 2 which is e nhv 0 5 mj cm 2. Typically such transitions involve resonances which can lead to strongly peaked cross section spectra.

Optical cross sections scattering and absorption of light by small particles underpin common natural phenomena such as the colors of the sky and the clouds the hues of rainbows and irises and the opalescence of some precious stones. They are also very valuable in discriminating weak features in a user s spectra. Enhancing the optical cross section is an enticing goal in light matter interactions due to its fundamental role in quantum and nonlinear optics.

Optical sectioning is the process by which a suitably designed microscope can produce clear images of focal planes deep within a thick sample. The standard unit of measurement is. Where r is the transition rate in units of s 1 σ is the transition cross section i is the optical intensity and h ν is the photon energy.

This is used to reduce the need for thin sectioning using instruments such as the microtome many different techniques for optical sectioning are used and several microscopy techniques are specifically designed to improve the quality of optical sectioning.