Calculation of the dispersion of the electro-optical and second harmonic coefficients from the refractive index dispersion

Fontana, M.D.; Abarkan, Mustapha; Salvestrini, Jean Paul

doi:10.1016/j.optmat.2013.11.020

Cited by 3 publications

(2 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The changes in the refractive index as a function of the incident beam energy indicate that inside the sample there are some interactions between photons and electrons . The dispersion of the refractive index can be described by Equation :

n^{2} = \frac{E_{0}^{2} - {(h ν)}^{normal2} + E_{normald} E_{normal0}}{E_{normal0}^{normal2} - {(h ν)}^{normal2}}

where n is the refractive index of the polymer, h represents the Planck's constant, ν is the frequency, E 0 denotes the average excitation energy for electronic transitions and E d is the dispersion energy.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the short and more rigid DDM segments might determine a little higher local ordering in comparison with bulky and flexible 6FADE units. Also, the E 0 could be correlated to the optical phenomena near band edges, especially with the direct band gap, indicating that the poly(EPI/6FADE) film exhibits lower optical absorption and higher optical gap than poly(EPI/DDM). Thus, the band gap ( E g ) values show that both PI films are highly transparent, given their wide optical band gap (Table ).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Insights on Light Dispersion in Semi‐Alicyclic Polyimide Alignment Layers to Reduce Optical Losses in Display Devices

Barzic¹,

Hulubei²,

Stoica³

et al. 2018

Macro Materials & Eng

View full text Add to dashboard Cite

Two polyimide structures are prepared from an alicyclic dianhydride and aromatic diamines, containing or lacking fluorine. The polymer films are characterized for display technology purposes. Light dispersion data of the studied samples are compared with those of some nematics to evaluate optical losses in the liquid crystal cell. It is shown for the first time that matching refractive indices of polyimide and nematic at several wavelengths is essential for reduction of Fresnel reflections, thus improving the device performance. Resistivity measurements indicate that rubbing generates a few surface charges on the surface of the fluorine‐derived polymer, which contribute to a more uniform orientation of liquid crystals, as supported by polarized microscopy analysis. Both pristine polyimide films exhibit a smooth surface with isotropic features, which are changed into anisotropic ones after rubbing, as a consequence of microgrooves’ appearance. Their thickness uniformity is affected by the structure of the diamine moieties. The adhesion of all nematics to the polyimide films is enhanced by the rubbing procedure.

show abstract