scholarly journals Slow Light Rainbow Trapping in a Uniformly Magnetized Gyromagnetic Photonic Crystal Waveguide

2021 ◽  
Vol 8 ◽  
Author(s):  
Jianfeng Chen ◽  
Qiumeng Qin ◽  
Chaoqun Peng ◽  
Wenyao Liang ◽  
Zhi-Yuan Li

We present a hybrid gyromagnetic photonic crystal (GPC) waveguide composed of different GPC waveguide segments possessing various cylinder radii and waveguide widths but biased by a uniform external magnetic field. We demonstrate in frequency and time domains that based on the strong coupling of two counter-propagating topologically protected one-way edge states, the intriguing slow light rainbow trapping (SLRT) of electromagnetic (EM) waves can be achieved, that is, EM waves of different frequencies can be slowed down and trapped at different positions without cross talk and overlap. More importantly, due to the existence of one-way edge states, external EM waves can be non-reciprocally coupled to the SLRT waveguide channel, although the incident position of the EM wave is far away from the waveguide channel. Besides, the frequency range of the slow light states can also be easily regulated by tuning the intensity of an external magnetic field, which is very beneficial to solve the contradiction between slow light and broad bandwidth. Our results can be applied to the design of high-performance photonic devices, such as an optical buffer, optical switch, and optical filter.

2013 ◽  
Vol 634-638 ◽  
pp. 2324-2331
Author(s):  
Hai Bo Hu ◽  
Qian Wang Chen ◽  
Ran Li ◽  
Xiang Kai Kong ◽  
Jian Chen

The carbon-encapsulated superparamagnetic colloidal nanoparticles (SCNps) were rigidized into soft solids by embedding the SCNps into polyacrylamide hydrogel matrixes under the induction of an external magnetic field. Stabilized by the balance of attractive (magnetic) and repulsive (electrostatic) forces, the SCNps form one-dimension photonic crystal structures along the direction of the external magnetic field and further the structures are frozen into the solidified polymer matrix. The polymer matrix embedded one-dimension photonic crystal structures can strongly diffract visible light and present brilliant color in the light. This novel and soft solid polymer matrix that could be shaped and sliced not only paves a new avenue for develop novel magnetic-responsive photonic crystal materials and devices, but also provides a method to observe the magnetic-induced self-assembly structures of the SCNps in media such as polyacrylamide hydrogel matrixs as a result of the ordered structures frozen into the polyacrylamide hydrogel matrixs. So we can reveal the relationship between their structure and color, and furthermore permit a systematic exploration on magnetically induced self-assembling dynamics, colloidal crystallography which have important significance in the large-scale industrial production in the future.


2014 ◽  
Vol 7 (7) ◽  
pp. 2250-2254 ◽  
Author(s):  
Ricardo H. Gonçalves ◽  
Edson R. Leite

The association of colloidal deposition of magnetorheological fluid in the presence of an external magnetic field with a sintering process facilitates the attainment of hematite photoanodes with high performance for water splitting.


Optik ◽  
2013 ◽  
Vol 124 (23) ◽  
pp. 6292-6297 ◽  
Author(s):  
Shahram Bahadori Haghighi ◽  
Rahim Ghayour ◽  
Babak Vakili

2015 ◽  
Vol 12 (4) ◽  
pp. 045202 ◽  
Author(s):  
Seyyed Hossein Asadpour ◽  
Hamid Reza Hamedi ◽  
Hamid Rahimpour Soleimani

2017 ◽  
Vol 52 (11) ◽  
pp. 1505-1517
Author(s):  
Arsalan Tayefeh ◽  
Mark Wiesner ◽  
Seyyed A Mousavi ◽  
Reza Poursalehi

The magnetic response of a polyamide nanocomposite membrane under applying a magnetic field has been modeled to evaluate elastic deformation order of magnitude. A PA-Fe3O4 nanocomposite membrane is considered to be modeled under influence of volume plane stress caused by a magnetic field. The modeling of the mechanical behavior of Fe3O4-PA nanocomposite membrane suggests that nanoparticle displacements within the nanocomposite, in the order of 200 nm under applying an external magnetic field, are greater than free volumes or porosities of the polyamide membrane. The membrane can be excited to mechanically vibrate by applying an alternating magnetic field lower than 0.1 T. As the results showed, there is an optimum nanoparticle size, %vol. loading and magnetic field strength to optimize such very small mechanical elastic deformations in the polymer, for controlling membrane functions. The perturbation and decreasing thickness of boundary layer and flow regime can be created by such vibrational elastic deformations on the membrane. It shows that the nanoparticle size has a more significant effect on membrane in-plane movement than their %vol. loading in the polyamide matrix. Decreasing loading of magnetic nanoparticles is very critical to fabricating high-performance membranes with appropriate and controllable magnetic and mechanical properties simultaneously. This phenomenon in vibrational mode might be exploited as a pathway to develop near surface mixing on the membrane, to hydrodynamically lower boundary layer thickness, control membrane separation behavior and enhance cleaning of the membranes, with inducing alternative magnetic fields.


2019 ◽  
Vol 33 (06) ◽  
pp. 1950034
Author(s):  
Yi-Heng Wu ◽  
Yun-Tuan Fang

The transmission properties of one-dimensional photonic crystal composed of the Gyromagnetic and gain medium are investigated. The energy loss due to the Gyromagnetic medium is compensated by adding one gain defect layer. From the analysis, it is found that both the nonreciprocal and enhancement effect are affected considerably by the incident angle, layer thickness, external magnetic field and gain coefficient. Specifically, it is demonstrated that the gain defect layer plays an important role in achieving nonreciprocal and enhancement transmission.


Sign in / Sign up

Export Citation Format

Share Document