Mirrorless lasing from nematic liquid crystals in the plane waveguide geometry without refractive index or gain modulation

2006 ◽  
Vol 89 (3) ◽  
pp. 031114 ◽  
Author(s):  
L. M. Blinov ◽  
G. Cipparrone ◽  
P. Pagliusi ◽  
V. V. Lazarev ◽  
S. P. Palto
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Plane Waveguide ◽  
Gain Modulation ◽  
Waveguide Geometry

scholarly journals Switchable Photonic Nanojet by Electro-Switching Nematic Liquid Crystals

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 72 ◽  
Author(s):  
Bintao Du ◽  
Jun Xia ◽  
Jun Wu ◽  
Jian Zhao ◽  
Hao Zhang
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Double Layer ◽  
Nematic Liquid Crystals ◽  
Surrounding Medium ◽  
Refractive Index Change ◽  
Electric Energy ◽  
Incident Wavelength ◽  
Photonic Nanojet ◽  
Energy Focusing

This paper first presents a switchable photonic nanojet (PNJ) generated by a polystyrene (PS) microsphere immersed in nematic liquid crystals (NLCs). The PNJ is switched by applying external voltage, which originates from the refractive index change in the surrounding medium caused by the field-induced realignment of liquid crystal molecules. By tuning the refractive index of NLCs larger or smaller than that of the PS microsphere, the PNJ can be switched off or on. Moreover, we present an optimization study to seek a better electric energy focusing property of the PNJ. Our results reveal that the switchability of PNJ can be optimized by applying a shorter incident wavelength, a double-layer microsphere, and a PS ellipsoid. The full width at half-maximum (FWHM) generated by the PS ellipsoid is narrower than that generated by the microsphere with a shorter incident wavelength. The intensity contrast of the PS ellipsoid is higher than that of the double-layer microsphere. As a whole, the switchability of PNJ can be best optimized by a PS ellipsoid. This should open the way for the development of integrated photonic devices.

Nonlinear effects in photonic crystal fibers filled with nematic liquid crystals

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Urszula Laudyn ◽  
Katarzyna Rutkowska ◽  
Robert Rutkowski ◽  
Mirosław Karpierz ◽  
Tomasz Woliński ◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Photonic Crystal ◽  
Low Power ◽  
Light Beam ◽  
Photonic Crystal Fibers ◽  
Nematic Liquid Crystals ◽  
Nonlinear Effects ◽  
The Creation ◽  
Crystal Fibers

AbstractWe have investigated the nonlinear propagation of light in photonic crystal fibers filled with nematic liquid crystals. We analyzed a configuration with a periodic modulation of the refractive index corresponding to a matrix of waveguides. Matrices of coupled waveguides allow observing a variety of new phenomena both for low power light beam propagation and with an existence of nonlinear effects. The opportunity for the creation of solitary waves caused by the interplay between diffraction and nonlinear effects in these kinds of fibers is investigated. At low power the propagating light beam spreads as it couples to more and more waveguides. When the intensity is increased the light modifies the refractive index distribution, inducing a defect in the periodic structure. The creation of such a defect can lead to a situation in which the light becomes self-localized and its diffractive broadening is eliminated. Eventually, in the case of positive Kerr-type nonlinearity, a discrete soliton can be created. In the case of negative nonlinearity the refractive index decreases with the optical power and can lead to bandgap shifting. The incident beam, with a frequency initially within the bandgap, is then turned outside the bandgap resulting in the changing of the propagation effect for the discrete diffraction effect. As a consequence the delocalization of the light can be observed.

scholarly journals Voltage-Controllable Guided Propagation in Nematic Liquid Crystals

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Hsin-Yu Yao ◽  
Shang-Min Yeh
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Single Channel ◽  
Coupling Effect ◽  
Nematic Liquid Crystals ◽  
The Self ◽  
External Voltage ◽  
Self Focusing ◽  
Guided Propagation ◽  
Adjacent Channels

Voltage-controllable guided channels are formed in a planar nematic liquid crystals cell. The director of liquid crystals can be aligned by applying external voltage, which results in a difference of the refractive index between two adjacent channels; therefore, the incidence beam can be coupled from one channel to another. First, we discussed the propagation of the beam and the self-focusing in a single channel; then we discussed the propagation of the beam and the coupling effect in the two channels. The results showed that the propagation of the beam can be selected in each channel by applying voltages in the two individual electrode channels.

scholarly journals Refraction of nonlinear beams by localized refractive index changes in nematic liquid crystals

2010 ◽  
Vol 82 (5) ◽  
Author(s):  
Gaetano Assanto ◽  
Antonmaria A. Minzoni ◽  
Noel F. Smyth ◽  
Annette L. Worthy
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Nonlinear Beams ◽  
Index Changes

Large extraordinary refractive index in highly birefringent nematic liquid crystals of dinaphthyldiacetylene-based materials

2013 ◽  
Vol 1 (27) ◽  
pp. 4222 ◽  
Author(s):  
Sungmin Kang ◽  
Shunpei Nakajima ◽  
Yuki Arakawa ◽  
Gen-ichi Konishi ◽  
Junji Watanabe
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Extraordinary Refractive Index

Measurement of the refractive index of nematic liquid crystals 5CB by means of x-ray interferometry

2014 ◽  
Author(s):  
V. P. Mkrtchyan ◽  
L. G. Gasparyan ◽  
T. K. Dadalyan ◽  
M. K. Balyan ◽  
A. V. Kuyumchyan
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
X Ray

scholarly journals Photonic logic based on molecular reorientation of nematic liquid crystals

1984 ◽  
Vol 313 (1525) ◽  
pp. 381-384
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Laser Beams ◽  
Molecular Reorientation ◽  
New Type ◽  
Index Changes

A new type of photonic logic, based on the use of nematic liquid crystals is proposed. The system takes advantage of the refractive-index changes induced by laser beams. Examples of AND, OR and NOR functions are presented.

Refractive index of nematic liquid crystals in the submillimeter wave region

1997 ◽  
Vol 36 (25) ◽  
pp. 6383 ◽  
Author(s):  
Toshiaki Nose ◽  
Susumu Sato ◽  
Koji Mizuno ◽  
Jongsuck Bae ◽  
Tatsuo Nozokido
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Submillimeter Wave ◽  
Wave Region
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