scholarly journals From chaos to stability in soliton mode-locked fibre laser system

2021 ◽  
Vol 67 (6 Nov-Dec) ◽  
Author(s):  
Morteza A. Sharif ◽  
K. Ashabi
Keyword(s):  
Laser System ◽  
Control Process ◽  
Stable State ◽  
Chaotic Regime ◽  
Fibre Laser ◽  
Control Parameters ◽  
Single Side ◽  
Encryption And Decryption ◽  
Encryption Decryption ◽  
Unstable States

Intracavity energy rate in a soliton mode-locked fibre laser is derived by solving the Haus master equation. The influence of net gain, absorber response, saturation energy, nonlinearity and absorption are investigated on stable/unstable states. Intracavity modes include the zeroth, first and higher order solitons. Accordingly, chaotic regime as well as breather modes is recognized as a conventional intracavity state. However, tuning the control parameters also results in a reverse bifurcation and thus returning to a stable state. Accordingly, a chaos-based encryption/decryption system is proposed taking the advantage of using a single-side control process; both the encryption and decryption procedures can be achieved by one of the actions of increasing/decreasing the control parameters.

Fibre laser system providing generation of frequency-modulated pulses with a spectral width exceeding the gain linewidth

2016 ◽  
Vol 46 (12) ◽  
pp. 1092-1096 ◽  
Author(s):  
I O Zolotovskii ◽  
D A Korobko ◽  
D A Stoliarov
Keyword(s):  
Laser System ◽  
Spectral Width ◽  
Fibre Laser

scholarly journals A Chaos based image Encryption Scheme using one Dimensional Exponential Logistic Map.

2019 ◽  
Vol 1 ◽  
pp. 223-237
Author(s):  
Terlumun Gbaden
Keyword(s):  
Correlation Coefficient ◽  
Chaotic Map ◽  
Logistic Map ◽  
Encryption Scheme ◽  
One Dimensional ◽  
Encryption And Decryption ◽  
Secret Keys ◽  
Encryption Decryption ◽  
Logistic Chaotic Map ◽  
Encrypted Images

The widespread use of images in various sectors of life makes its protection increasingly necessary and important. An improvement over encryption and decryption algorithm using exponential logistic chaotic map was proposed. In this work, we adopt an encryption/decryption strategy for colour images using the exponential logistic chaotic map. The proposed encryption/decryption algorithms are implemented in MATLAB for computer simulation. The experimental results indicate that the proposed algorithms can be used successfully to encrypt/decrypt images with secret keys. The performance analysis using histogram uniformity analysis and correlation coefficient show that the algorithms give larger space, quick speed and easy to realize. The encrypted images have good encryption effect and low correlation coefficient rendering it a good candidate for confidential and secure means of transmitting image information in untrusted networks.

scholarly journals Study A Public Key in RSA Algorithm

2020 ◽  
Vol 5 (4) ◽  
pp. 395-398
Author(s):  
Taleb Samad Obaid
Keyword(s):  
Private Information ◽  
Original Data ◽  
Prime Numbers ◽  
Public Key ◽  
The Internet ◽  
Sensitive Information ◽  
Rsa Algorithm ◽  
Encryption And Decryption ◽  
Main Disadvantage ◽  
Encryption Decryption

To transmit sensitive information over the unsafe communication network like the internet network, the security is precarious tasks to protect this information. Always, we have much doubt that there are more chances to uncover the information that is being sent through network terminals or the internet by professional/amateur parasitical persons. To protect our information we may need a secure way to safeguard our transferred information. So, encryption/decryption, stenographic and vital cryptography may be adapted to care for the required important information. In system cryptography, the information transferred between both sides sender/receiver in the network must be scrambled using the encryption algorithm. The second side (receiver) should be outlook the original data using the decryption algorithms. Some encryption techniques applied the only one key in the cooperation of encryption and decryption algorithms. When the similar key used in both proceeds is called symmetric algorithm. Other techniques may use two different keys in encryption/decryption in transferring information which is known as the asymmetric key.  In general, the algorithms that implicated asymmetric keys are much more secure than others using one key.   RSA algorithm used asymmetric keys; one of them for encryption the message, and is known as a public key and another used to decrypt the encrypted message and is called a private key. The main disadvantage of the RSA algorithm is that extra time is taken to perform the encryption process. In this study, the MATLAB library functions are implemented to achieve the work. The software helps us to hold very big prime numbers to generate the required keys which enhanced the security of transmitted information and we expected to be difficult for a hacker to interfere with the private information. The algorithms are implemented successfully on different sizes of messages files.

scholarly journals Barrel Shifter Physical Unclonable Function Based Encryption

Cryptography ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 22 ◽  
Author(s):  
Yunxi Guo ◽  
Timothy Dee ◽  
Akhilesh Tyagi
Keyword(s):  
Logistic Regression ◽  
Manufacturing Process ◽  
Ring Oscillator ◽  
Key Generation ◽  
Physical Unclonable Functions ◽  
Encryption And Decryption ◽  
Barrel Shifter ◽  
Transmission Gates ◽  
Encryption Decryption ◽  
Randomness Tests

Physical Unclonable Functions (PUFs) are designed to extract physical randomness from the underlying silicon. This randomness depends on the manufacturing process. It differs for each device. This enables chip-level authentication and key generation applications. We present an encryption protocol using PUFs as primary encryption/decryption functions. Each party has a PUF used for encryption and decryption. This PUF is constrained to be invertible and commutative. The focus of the paper is an evaluation of an invertible and commutative PUF based on a primitive shifting permutation network—a barrel shifter. Barrel shifter (BS) PUF captures the delay of different shift paths. This delay is entangled with message bits before they are sent across an insecure channel. BS-PUF is implemented using transmission gates for physical commutativity. Post-layout simulations of a common centroid layout 8-level barrel shifter in 0.13 μ m technology assess uniqueness, stability, randomness and commutativity properties. BS-PUFs pass all selected NIST statistical randomness tests. Stability similar to Ring Oscillator (RO) PUFs under environmental variation is shown. Logistic regression of 100,000 plaintext–ciphertext pairs (PCPs) fails to successfully model BS-PUF behavior.

Thermal and morphological analysis of the interaction effect of different assist gases with gas-filled closed-cell aluminium foam during laser cutting process

2020 ◽  
pp. 095440542091725
Author(s):  
Mohammad Shahid Raza ◽  
Susmita Datta ◽  
Partha Saha
Keyword(s):  
Interaction Effect ◽  
Laser Cutting ◽  
Laser System ◽  
Aluminium Foam ◽  
Cutting Process ◽  
Fibre Laser ◽  
Closed Cell ◽  
Structural Applications ◽  
In Situ Reactions

Closed-cell aluminium foam, a porous structure, is effectively used for insulation, structural applications, packaging and filtering. Cutting of aluminium foam with the help of fibre laser is an efficient method due to the inherent advantages of fibre laser. Laser cutting of aluminium foam was carried out using a 2-kW fibre laser system for varying process parameters and different assist gas environments. Use of different foaming agents results in the generation of gas-filled pores. During the laser cutting process, the interaction of these gas-filled pores with assist gas results in in-situ reactions, generating different kerf quality. This interaction effect of foam cutting was reported using optical, metallurgical and thermal analysis. Thermal cycles were recorded to understand the occurrence of different in-situ reactions. From the temperature signal for different assist gases, oxygen showed the highest temperature, followed by nitrogen and argon. Argon assist gas gave minimum kerf width, while nitrogen assist gas produced minimum dross. Elemental and phase analysis showed the presence of new compounds and intermetallics in the cut section that stipulated the occurrence of in-situ reactions during the cutting process. The internal pore surface showed the presence of spatter in case of oxygen, while nitrogen and argon gas environment showed relatively less pore-clogging.

New barbituric acid derivatives for data encryption and decryption based on the mechanochromic fluorescence effect

The Analyst ◽  
2020 ◽  
Vol 145 (15) ◽  
pp. 5325-5332
Author(s):  
Hanjun Zhang ◽  
Zhen Xu ◽  
Furong Tao ◽  
Yan Li ◽  
Yuezhi Cui ◽  
...  
Keyword(s):  
Optical Properties ◽  
Barbituric Acid ◽  
Data Encryption ◽  
Fluorescence Properties ◽  
Encryption And Decryption ◽  
Encryption Decryption ◽  
Barbituric Acid Derivatives ◽  
Fluorescence Effect

CB-Ph and CB-Me have similar color and fluorescence properties, while they exhibit specific differences under the same stimulus. Based on the unique optical properties of CB-Ph and CB-Me, a new data encryption–decryption technology is developed.

Dual-color, power-scalable DFB fibre laser system for kHz-linewidth terahertz generation

2007 ◽  
Author(s):  
Finn Eichhorn ◽  
Jens Engholm Pedersen ◽  
Claus Friis Pedersen ◽  
Peter Uhd Jepsen
Keyword(s):  
Laser System ◽  
Fibre Laser ◽  
Terahertz Generation ◽  
Dual Color

Ant Colony Algorithm Application In Glass Fiber Textile Machine Parameter Tuning

2012 ◽  
Vol 462 ◽  
pp. 71-76 ◽  
Author(s):  
Li Hong Zhang ◽  
Shu Qian Chen ◽  
Gui Zhi Bai
Keyword(s):  
Glass Fiber ◽  
Pid Control ◽  
Ant Colony Algorithm ◽  
Control Process ◽  
Parameter Tuning ◽  
Integral Function ◽  
Parameters Optimization ◽  
Ant Colony ◽  
Control Parameters ◽  
Optimization Strategy

In glass fiber textile process, non-axis volume cloth drive motor with glass fabric volume increases, increasing the pressure on the drive shaft, moreover, because of cloth non-axis volume makes the pressure in the process of change is evident, that causes the motor load changing constantly, the traditional PID control system controller cannot timely tracking response. In order to solve the problem which the control parameters optimizes, improves the system performance, proposed a new Ant colony algorithm PID parameters optimization strategy, this solution can combine characteristics that Ant colony algorithm can fast find the most superior parameter solution stably and PID can precise adjustment. In the control process, taken the PID parameters as a colony of ants, used to control the absolute error integral function as the optimization objective, dynamically adjust the PID control parameters in the control process, so as to realize the PID parameters on-line tuning.

Sign in / Sign up

Export Citation Format

Share Document