- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Adaptive Pixel-Selection Fractional Chaotic Map Lattices for image cryptography
摘要： Chaotic theory has been employed in cryptography application for establishing a sequence of data closest to pseudorandom number. Image cryptography with Chaotic Map Lattices (CML) uses the chaos parameters, the number of iterations and the number of cycles for encryption as secret keys. Amount of secret keys has a great impact on security in cryptography. Adaptive Pixel-Selection Fractional Chaotic Map Lattices (APFCML) enhances the encryption security by introducing a novel non-integer fractional order concept as secret keys. Fractional chaos is modified chaos with a fractional differential equation containing derivatives of non-integer order. A non-integer order has an effect on the range of chaos's parameter. Moreover, the encryption sequence has been adaptively selected based on another chaos generator. In the experiments, the measurement indices of originality preservation, visual inspection, and statistical analysis are used to evaluate the performance of the proposed APFCML compared to that of the original CML.
关键词： fractional logistic,bifurcation diagram,image cryptography,Lyapunov exponent,Chaotic
更新于2025-09-23 15:19:57
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Numerical study of Riskena??Nummedala??Grahama??Haken instability in mid-infrared Fabrya??P??rot quantum cascade lasers
摘要： We review our recent theoretical studies on multimode instabilities in Fabry–Pérot cavity mid-infrared quantum cascade lasers (QCLs) caused by parametric excitation of Rabi flopping oscillations. Numerical simulations are based on the semiclassical traveling wave Maxwell–Bloch equations. QCLs with a few mm cavity without an absorber exhibit intermittent RNGH self-pulsations, while regular self-pulsations are possible in short-cavity QCLs, with the cavity length of 100 μm or smaller. However, the second threshold in short-cavity QCLs is significantly increased compared to the values for a few mm long devices. We provide here a new insight on RNGH instability via bifurcation analysis of the output waveform and studies of the recurrence period density entropy. We propose an interpretation of the broadening/narrowing of the optical spectrum of a QCL i.e. switching the RNGH instability on and off observed in experiment.
关键词： Quantum cascade laser,RNGH instability,Self-pulsations,Bifurcation diagram,Spatial hole burning
更新于2025-09-16 10:30:52