All-optical switching with cascaded two-stage MZIs using saturable absorption accompanied by refractive-index change in graphene

2014 ◽  
Author(s):  
Misaki Takahashi ◽  
Hiroki Kishikawa ◽  
Nobuo Goto ◽  
Shin-ichiro Yanagiya
Keyword(s):  
Refractive Index ◽  
Optical Switching ◽  
Refractive Index Change ◽  
Saturable Absorption ◽  
Two Stage ◽  
Index Change ◽  
All Optical ◽  
All Optical Switching

DFB Waveguide All-Optical Switching Devices Employing Pump-Induced Refractive Index Change in GaInAsP

2007 ◽  
Vol 31 ◽  
pp. 206-208 ◽  
Author(s):  
Tetsuya Mizumoto ◽  
Yoichi Akano ◽  
Kazuhiko Tamura ◽  
Masaki Yoshimura
Keyword(s):  
Refractive Index ◽  
Optical Switching ◽  
Refractive Index Change ◽  
Distributed Feedback ◽  
Temporal Response ◽  
Index Change ◽  
All Optical ◽  
Optical Switching Devices ◽  
All Optical Switching ◽  
Switching Devices

A pump-induced refractive index change was measured in a passive GaInAsP waveguide together with its temporal response. Also, the temporal response of distributed feedback (DFB) waveguide transmittance modulated by the pump-induced index change was experimentally investigated for an application to all-optical switching devices.

scholarly journals All-optical switching using a new photonic crystal directional coupler

2015 ◽  
Vol 4 (1) ◽  
pp. 63 ◽  
Author(s):  
B. Vakili ◽  
S. Bahadori-Haghighi ◽  
R. Ghayour
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Communication Systems ◽  
Optical Switching ◽  
Directional Coupler ◽  
Refractive Index Change ◽  
Control Signal ◽  
Index Change ◽  
All Optical ◽  
All Optical Switching

In this paper all-optical switching in a new photonic crystal directional coupler is performed.  The structure of the switch consists of a directional coupler and a separate path for a control signal called “control waveguide”. In contrast to the former reported structures in which the directional couplers are made by removing a row of rods entirely, the directional coupler in our optical switch is constructed by two reduced-radius line-defect waveguides separated by the control waveguide. Furthermore, in our case the background material has the nonlinear Kerr property. Therefore, in the structure of this work, no frequency overlap occurs between the control waveguide mode and the directional coupler modes. It is shown that such a condition provides a very good isolation between the control and the probe signals at the output ports. In the control waveguide, nonlinear Kerr effect causes the required refractive index change by the presence of a high power control (pump) signal. Even and odd modes of the coupler are investigated by applying the distribution of the refractive index change in the nonlinear region of a super-cell so that a switching length of about 94 µm is obtained at the wavelength of 1.55 µm. Finally, all-optical switching of the 1.55 µm probe signal using a control signal at the wavelength of 1.3 µm, is simulated through the finite-difference time-domain method, where both signals are desirable in optical communication systems. A very high extinction ratio of 67 dB is achieved and the temporal characteristics of the switch are demonstrated.

Dynamics of reverse saturable absorption and all-optical switching in C_60

1994 ◽  
Vol 11 (8) ◽  
pp. 1356 ◽  
Author(s):  
Chunfei Li ◽  
Lei Zhang ◽  
Ruibo Wang ◽  
Yinling Song ◽  
Yuxiao Wang
Keyword(s):  
Optical Switching ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
All Optical ◽  
All Optical Switching

Study on All Optical Switching Effect of Excited State Proton Transfer Organic Molecule 3-Hydroxyflavone

2012 ◽  
Vol 482-484 ◽  
pp. 830-834
Author(s):  
Yang Xue Guo ◽  
Xiang Hong Kong ◽  
Wei Yang ◽  
Jia Jin Zheng
Keyword(s):  
Refractive Index ◽  
Excited State ◽  
Proton Transfer ◽  
Laser Beam ◽  
Nonlinear Refractive Index ◽  
Optical Switching ◽  
Switching Effect ◽  
All Optical ◽  
Excited State Proton Transfer ◽  
All Optical Switching

Abstract: We report the dependence of the all optical switching effect of 3-hydroxyflavone (3-HF) on the efficiency of excited state proton transfer (ESPT) using pump probe method. A cw probe laser beam of 632.8nm passing through the sample is switched off by a 35ps pulse pump laser beam of 355nm. We also measured the nonlinear refractive index of 3-HF in different solvents by using z-scan technique. The results show that the optical switching effect will be more obvious when the efficiency of excited state proton transfer is improved, while not proportional to the nonlinear refractive index of 3-HF.

TYPE-II SUPERLATTICES AND VARIABLE OVERLAP SUPERLATTICES IN TOTAL INTERNAL REFLECTION SWITCHES FOR THE LONGWAVE INFRARED

1993 ◽  
Vol 02 (03) ◽  
pp. 415-436 ◽  
Author(s):  
E.R. YOUNGDALE ◽  
J.R. MEYER ◽  
C.A. HOFFMAN ◽  
F.J. BARTOLI ◽  
W.I. WANG
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Total Internal Reflection ◽  
Optical Switching ◽  
Refractive Index Change ◽  
Realistic Model ◽  
Internal Reflection ◽  
Type Ii ◽  
Index Change ◽  
Type Ii Superlattices

We derive explicit criteria for the properties required of a semiconductor nonlinear medium suitable for use in all-optical switching devices employing total internal reflection. Transmission as a function of laser intensity and film thickness has been calculated using a realistic model for penetration of the evanescent beam under TIR conditions. Requirements based on these results include a large nonlinear refractive index, large index change at saturation and small absorption coefficient. We show that unlike previously-studied semimetals and narrow-gap semiconductors, Type-II superlattices such as InAs-GaSb and variable-overlap superlattices (variants of Type-II which include a spacer between the layer containing the conduction-band minimum and that containing the valence band maximum) such as InAs-AlSb-GaSb hold prospects for satisfying all of these requirements simultaneously. As the free carrier lifetime will have a crucial influence on device performance, we have initiated a systematic experimental study of electron-hole recombination in InAs-based superlattices. From degenerate and nondegenerate four-wave mixing experiments, we have also determined nonlinear optical coefficients as a function of difference frequency and intensity. An InAs-GaSb superlattice has been found to display a refractive index change of ≈ 0.1, as well as device figures of merit which slightly surpasses any previously reported for weakly-saturating nonlinearities at CO 2 wavelengths. It is anticipated that future experiments on Type-II superlattices with longer lifetimes may yield nearly two orders of magnitude additional improvement in the nonlinear refractive index.

scholarly journals High Quality Factor Silicon Membrane Metasurface for Intensity-Based Refractive Index Sensing

Optics ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 193-199
Author(s):  
Andrea Tognazzi ◽  
Davide Rocco ◽  
Marco Gandolfi ◽  
Andrea Locatelli ◽  
Luca Carletti ◽  
...  
Keyword(s):  
Refractive Index ◽  
Quality Factor ◽  
Refractive Index Change ◽  
Periodic Array ◽  
Silicon Membrane ◽  
High Quality ◽  
Index Change ◽  
Sensing Mechanism ◽  
Refractive Index Sensing ◽  
All Optical

We propose a new sensing device based on all-optical nano-objects placed in a suspended periodic array. We demonstrate that the intensity-based sensing mechanism can measure environment refractive index change of the order of 1.8×10−6, which is close to record efficiencies in plasmonic devices.

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