Data Item _diffrn_scan_frame.polarizn_Stokes_I

General

Item name
_diffrn_scan_frame.polarizn_Stokes_I
Category name
diffrn_scan_frame
Attribute name
polarizn_Stokes_I
Required in PDB entries
implicit
Used in currrent PDB entries
No

Item Description

The quantity Ip+In+Inp, where Ip is the intensity (amplitude squared) of the electric vector in the plane of polarization, In is the intensity (amplitude squared) of the electric vector in the plane of the normal to the plane of polarization, and Inp is the intensity (amplitude squared) of the non-polarized (incoherent) electric vector. This is an average or other representative sample of the frame. This is the first of the Stokes polarization parameters, I, Q, U, V [also known as I, M, C, S; see Berry et al. (1977)]. If the absolute intensity is not known, the value 1.0 is assumed for I, and all four Stokes parameters are dimensionless. When the absolute intensity is known, all four Stokes parameters are in units of watts per square metre. Note that, if the polarized intensity Ip+In is required, (Ip+In)2 is the sum of Q2+U2+V2. Reference: Berry, H. H., Gabrielse, G. & Livingston, A. E. (1977). 'Measurement of the Stokes parameters of light', Appl. Optics, 16:12, 3200--3205.

Data Type

Data type code
float
Data type detail
float item types are the subset of numbers that are the floating numbers.
Primitive data type code
numb
Regular expression
-?(([0-9]+)[.]?|([0-9]*[.][0-9]+))([(][0-9]+[)])?([eE][+-]?[0-9]+)?
Default value
1.0

Allowed Boundary Conditions

Minimum Value Maximum Value
0.0

+∞