Field plane polarized

Plane-polarized electromagnetic radiation showing the electric field, the magnetic field, and the direction of propagation. 

Electric field component of plane-polarized electromagnetic radiation. 

Fig. 7. Fluorescence polarization (FP). (a) The formation of the large FITC—protein A—IgG complex which leads to a net increase in plane polarized light transmitted from the solution. Molecular weights of the protein A-FITC, IgG, and complex are ca 43,000, 150,000, and 343,000, respectively, (b) Detection of IgG by fluorescence polarization immunoassay using A, a laboratory fluorimeter where (O) represents AP = change in polarization, and B, a portable detection unit where (D) is —fiV = change in voltage (27). The field detector proved to be more sensitive than the fluorimeter.

Information about the properties of the sample are contained in the complex ratio, p, of the Fresnel coefficients of reflection of the parallel (rp) and perpendicular (rg) incident plane polarized electrical field vectors. 

The electric field of plane-polarized light oscillates in a single plane. It can be prepared hy passing ordinary, unpolarized light through a polarizer, which consists of a material that allows the light to pass only if the electric field is aligned in a certain direction. 

Figure 5.11 The plane of oscillation of the electrical field of plane-polarized light. In this example the plane of polarization is vertical.

If the foregoing created the impression that the electric and magnetic vectors of a propagating electromagnetic field are confined to vibrate in fixed planes, that was unintentional. A field like that would be plane polarized and to create that requires a special device known as a polarizer. Ordinary unpolarized light consists of an array of plane waves that are randomly oriented with respect to a plane perpendicular to the directions of propagation. 

Freely suspended films provide a perfect homeotropic alignment of smectic LCs since the layers always orient parallel to the LC/air interface.33 The director structure in such films can then be determined by analyzing the optical properties of plane-polarized light reflected from the surface of the films at a slightly oblique angle.34 The technique gains additional power when electrodes are added to the setup, allowing observation of the behavior of the films in the presence of an electric field parallel to the plane of the film.35... 

Figure 19.2 evidently shows the electric field of a plane-polarized light which consists of two components of fixed magnitude rotating in opposite directions to one another the right circularly polarized light and the... 

FIGURE 3.10 The instantaneous electric (Ev) and magnetic (H. ) field strength vectors of a plane-polarized light wave as a function of position along the axis of propagation (jc) (from Calvert and Pitts, 1966). 

A simple and practical way to achieve the field enhancement is to use backside illumination of a dielectric plate, for instance a cover glass, in a standard DLW geometry with an oil-immersion focusing lens. According to the Fresnel formulas for the right angle incidence (0, = 0°), the coefficients of the in-plane ( ) polarized amphtudes of transmitted and reflected electric fields are, respectively ... 

When the incident electric field is polarized perpendicular to the xz plane (Case II), the asymptotic scattered field is given by (8.33) with anl replaced by -anll and bnl replaced by -bnll. 

In the most general case, the above two equations mean that the electric field vector traces an ellipse in the j>z plane. There are two special cases of note in this general situation. If the phase difference between the two components of the field (5K -5.) is zero or some integral multiple of 7r, the ellipse flattens to a line. If the phase difference is t/2 or any odd integral multiple of tt/2 and the amplitudes of the two components are equal, the ellipse is rounded to a circle. In the former case we speak of the radiation as being plane polarized, and in the latter case as being circularly polarized. 

The last term in Eq. (1) describes the coupling to the laser field which has the form (t) = 00(t)0(r — t) sin2(7rt/r) cos(flt), where 0 is the amplitude, r the duration, and the center frequency of the pulse. The dipole moment vector is oriented in the plane of the molecule da0 are the respective matrix elements. Here, we will focus on the excitation of the stretching vibration which in our coordinate system is mostly polarized along the x axis. Thus, we will take into account only the x component of the dipole moment, assuming that the laser field is polarized accordingly [10],... 

Figure 18-1 Plane-polarized electromagnetic radiation of wavelength K. propagating along the x-axis. The electric field of plane-polarized light is confined to a single plane. Ordinary, unpolarized light has electric field components in all planes.

---