Главная страница | Контакты | Случайная страница Автомобили Астрономия Биология География Дом и сад Другие языки Другое Информатика История Культура Литература Логика Математика Медицина Металлургия Механика Образование Охрана труда Педагогика Политика Право Психология Религия Риторика Социология Спорт Строительство Технология Туризм Физика Философия Финансы Химия Черчение Экология Экономика Электроника

THE THEORY OF NLC LAYER DEFORMATION

The light intensity over NLC layer I(x, y) modulated by deformed NLC structure is described by equation:

I(x, y) = I₀ Sin²[δ(x,y)/2] (1)

The phase delay δ(x, y) caused by the NLC birefringence:

H is the thickness of NLC; n (x, y) is film reflective index of deformed zone; n₀ is non-deformed layer the refractive index. If the orientation has no twist deformation then only orientation bending occurs, hence:

n(x,y,z)=[n_e^-2Sin²φ(x,y,z) +n₀^-2Cos²φ(x, y, z)]^-1/2 (3)

φ(x,y,z) is the deflection angle of the long axis of NLC molecules; n_o, n_e are the refractive indices of NLC layer for ordinary and extraordinary polarization. The high value of NLC optical anisotropy permits to use very thin layer to obtain sufficient value of phase delay.

The theory of NLC layer deformations near the structural defects or obtained by magnetic or electrical fields is developed and described in paper³. The most interesting and practically important case is the detecting of structural inhomogeneities in different materials (for example, on the solid crystals surface), shown on fig. 1b (C). The theory gives the distribution of NLC molecules orientation near the structural defect (figure 3).

Figure 3. Solitary structural defect and induced local reorientation of NLC molecules³.

The NLC molecules orientation induced by structural inhomogeneities is described by equation:

(4)

The discussed theory was used for comments the results of experimental examination solid components structures of different solutions and other materials. It gives the possibility to calculate parameters of external fields.