Chaotic Laser Research Articles

Progress of Chaotic Semiconductor Lasers and Their Applications (Invited)

Progress of Chaotic Semiconductor Lasers and Their Applications (Invited)

Dynamics of polarization components of chaotic fiber laser

Dynamics of polarization components of chaotic fiber laser

Ultrafast Resource Allocation by Parallel Bandit Architecture Using Chaotic Lasers for Downlink NOMA Systems

Ultrafast Resource Allocation by Parallel Bandit Architecture Using Chaotic Lasers for Downlink NOMA Systems

Synchronization of complexity enhanced chaos in semiconductor lasers

In synchronized chaotic lasers based secure key distribution and other encrypted communications, presence of the time delay signature in chaos poses a threat to security. So the transmitter and receiver lasers should preferably be operated in complexity enhanced chaotic regime where the time delay signature is hidden. However, achieving good synchronization in experiments in such regime is challenging. We report experimental demonstration of achieving excellent synchronization between two semiconductor lasers even when both the lasers are operating in complexity enhanced chaotic regime with absolutely no time delay signature present in their output. This chaotic regime is ensured by evaluating the auto correlation function, permutation entropy and spectrum analysis of the time series. As a measure of synchronization, cross-correlation coefficient of 0.923 is achieved between the transmitter and receiver lasers. This results are of immense importance in chaos based secure key distribution and other encrypted communication schemes.

Loss compensated fiber loop ring-down system driven by random distributed multi-pulse laser

The sensing characteristics of loss compensated fiber loop ring-down (FLRD) system driven by random distributed multi-pulse have been analyzed. We used a random distributed multi-pulse laser to drive a fiber loop with loss compensation of erbium-doped fiber amplifier (EDFA) and analyzed the distortion of exponential attenuation curves, sensitivity and baseline stability of the system. The performance is compared with those of loss compensated FLRD system driven by single pulse and chaotic laser. The loss compensated FLRD theoretical model is discussed by the transmission equation of EDFA and finite element analysis. The performance of loss compensated FLRD system driven by random distributed multi-pulse under different injection optical powers is analyzed under the influence of gain saturation effect of EDF and amplified spontaneous emission (ASE). The results show that the random distributed multi-pulse system has higher R-square of exponential attenuation curves and better baseline stability than the single-pulse system. The increase of injection optical power has the least influence on the sensitivity reduction of random distributed multi-pulse system. The random distributed multi-pulse laser has better performance than single-pulse laser and chaotic laser in loss compensated FLRD system.

Optical time domain reflectometry based on a self-chaotic circular-sided microcavity laser.

A self-chaotic circular-sided square microcavity laser, with a chaos bandwidth of 12.9GHz and a flatness of ±3d B, was applied in optical time domain reflectometry (OTDR). Using the broadband chaos laser, we demonstrated a range resolution of 4.5mm and a 25-km detection distance experimentally. The solitary wide-bandwidth microcavity chaos laser, without the extra correlation peaks in optical feedback chaotic lasers, has shown potential advantages for correlation OTDR in practical application.

A No-Chatter Single-Input Finite-Time PID Sliding Mode Control Technique for Stabilization of a Class of 4D Chaotic Fractional-Order Laser Systems

Over the past decade, fractional-order laser chaotic systems have attracted a lot of attention from a variety of fields, including theoretical research as well as practical applications, which has resulted in the development of a number of different system classes. This paper introduces a novel single-input finite-time PID sliding mode control (SMC) technique to stabilize a specific group of unknown 4-dimensional chaotic fractional-order (FO) laser systems. By combining the PID concept with the FO-version of the Lyapunov stability theory, a novel finite-time PID SMC strategy has been developed, which effectively mitigates chaotic behavior in the mentioned unknown 4-dimensional chaotic FO laser system. This method makes use of a characteristic of FO chaotic systems known as boundedness, which is used here. Notably, the control input’s sign function, which is responsible for undesirable chattering, is transformed into the fractional derivative of the control input. This transformation results in a smooth and chattering-free control input, further enhancing the method’s performance. To demonstrate the efficacy of the proposed chattering-free–finite-time PID SMC technique, two numerical scenarios are presented, showcasing its efficient performance in stabilizing the unknown 4-dimensional chaotic FO laser system. These scenarios serve as illustrations of the method’s potential for practical applications.

Recognition of Noisy Digital Images Using the Asymmetric Coupling Semiconductor Chaotic Lasers Network

In this work, we construct a model of an asymmetrically coupled network of semiconductor chaotic lasers in order to recognize noisy digital images of digits 0–9, derived from different samples in the digital image sets 0–9 found within the MNIST dataset. Here, the lasers network consists of eight asymmetrically coupled semiconductor lasers. The chaotic lasers network is driven by the external inputs, which encode one noise digital image to be recognized. The outputs of the chaotic lasers network driven by a total of 40 samples from the digital image sets 0–9 are utilized as ten sets of reference signals. The output of the chaotic lasers network induced by one noisy digital image is used as a test signal. By judging the maximum of the correlations of the test signal with the ten sets of reference signals, all noisy digital images 0–9 can be recognized well under different noises. Moreover, we further explore the recognition rate for each noisy digital image under different noises and a fixed injection strength. It is found that all noisy digital images can be recognized well under a certain low injection strength. The recognition-rates of all noisy digital images can further decrease to a certain extent under higher noise and a fixed the injection strength. The injection strength has little influence on the recognition rate of one noise digital image target with lower noise. The recognition rate under higher noise maintains a higher value (more than 0.9) when the injection strength is smaller than a certain value, but for the larger injection strength, the recognition rate exhibits further decrease. The modeled chaotic lasers network can play the role of photonic accelerators for the recognition of the noisy digital images.

High performance multi-image encryption based on temporal-spatial double random ghost coding

A high performance multi-image encryption method is presented by using the temporal-spatial double random ghost coding (TSDRGC). As an original idea in optical encryption, TSDRGC employs the chaotic lasers as light sources instead of conventional lasers. The random fluctuations of the chaotic laser can be seen as the new temporal security keys introduced into the cryptosystem, except the random illumination patterns used usually in the conventional ghost imaging as a set of spatial security keys. In the encryption process, all the images can be optically encoded in parallel and the time consumed by the encryption process does not increase compared to encrypting an image alone. Meanwhile, a decryption algorithm is proposed to achieve high quality decryption of each image independently while reducing the bit-width requirement. The simulations demonstrate the excellent performance of the scheme in terms of security, capability and robustness.

Thermal Modulation of a Chaotic Fiber Laser by Using a Phase-Shifted Fiber Bragg Grating

Thermal Modulation of a Chaotic Fiber Laser by Using a Phase-Shifted Fiber Bragg Grating

Optical cryptographic communications with non-identical chaotic laser systems

"We report secure data transmission performed using chaotic lasers with different external cavity geometries and applying the chaotic masking method based on subcarrier and phase modulations of the chaotic optical carrier. Two semiconductor lasers with similar multimode emission spectra and self-optical feedback provided, respectively, by ring and linear external cavities, were optically coupled and chaotically synchronized into a master – slave scheme. The transmitted message frequency modulates the radio frequency signal which modulates in phase the master chaotic carrier. Based on the robustness of the used encryption method and the synchronization characteristics of the two lasers, the decryption is conducted by the simple radio frequency spectrum monitoring of the slave emission."

Millimeter-wave noise generation based on a monolithically integrated dual-mode chaotic laser.

A millimeter-wave noise generation scheme is proposed in this paper. The scheme is based on a monolithically integrated dual-mode chaotic laser, which consists of a distributed Bragg feedback (DFB) section, a phase section, and an optical amplification section. The output spectrum state of the dual-mode laser can be controlled by adjusting the injection current in the three regions. The monolithically integrated dual-mode chaotic laser has stable chaotic output and can be used as a light source for integrated millimeter-wave noise source. As a feasibility demonstration, a dual-mode chaotic laser with a mode interval of 2.05 nm was generated in the experiment, the optical mixing on a photodetector produced millimeter-wave noise with a center frequency of 259 GHz and a bandwidth of 44 GHz (237-281 GHz), achieving a typical value of excess noise ratio of 47 dB. It has the advantages of high noise source utilization, small noise source volume, and high integration.

External Filtered Modes of a Quantum Dot Laser Under the Influence of Double-Filtered Optical Feedback

When semiconductor lasers SLs are exposed to filtered optical feedback (FOB), they behave in two different ways. Under weak or strong feedback, the first is a singularly stable longitudinal mode with a small linewidth. The second is the so-called coherence breakdown condition, which also includes low frequency fluctuations (LFF) and chaotic oscillations. The latter has received a lot of attention recently due to the possible uses of chaotic lasers in chaotic lidar, covert communications, and chaotic correlation time-domain optical reflectometers, while the former has received a lot of research in recent years. We investigate the behavior of a quantum dot (QD) semiconductor laser subject to FOF from two separate external cavities both, numerically and experimentally. Our findings show that the second FOF allows for rich adjustment of the laser frequency. Our analysis of double-filtered optical feedback (DFOF) lasers is on fundamental solutions, sometimes referred to as continuous waves (CW) or external filtering modes (EFM), which result in a QD laser output with constant amplitude and frequency. The time delay suppression is dependent on the spectral width of the filter and how far it is from the solitary laser frequency, according to numerical calculations.

A new encryption scheme for RGB color images by coupling 4D chaotic laser systems and the Heisenberg group

A new encryption scheme for RGB color images by coupling 4D chaotic laser systems and the Heisenberg group

Investigation of Doppler Frequency Shift Effect on the Performance of Four-Channel Space Chaotic Laser Communication

In this article, the wavelength division multiplexing (WDM) technology is applied to the space chaotic laser communication system. We deduce the bit error rate (BER) model of multi-channel space chaotic laser communication with Doppler frequency shift. Based on the BER model, the effect of Doppler frequency shift on the performance of four-channel space chaotic laser communication systems on the synchronous orbit(GEO)-low earth orbit(LEO) and GEO-mid earth orbit(MEO) has been discussed in detail. The numerical simulation results indicate that the effect of Doppler frequency shift on GEO-LEO system is much less than GEO-MEO system. Therefore, the Doppler frequency shift effect of GEO-LEO system can be overcome by redundant design, and the Doppler frequency shift effect of GEO-MEO system must be paid more attention to the optimum design. Besides, the relationship between the performance of communication system and frequency shift under different channels are similar. The result has an important implication for reducing the complexity of the system design. These results of the article are significant for the design of the four-channel space chaotic laser communication system.

High-speed photon correlation monitoring of amplified quantum noise by chaos using deep-learning balanced homodyne detection

Precision experimental determination of photon correlation requires massive amounts of data and extensive measurement time. We present a technique to monitor second-order photon correlation g(2)(0) of amplified quantum noise based on wideband balanced homodyne detection and deep-learning acceleration. The quantum noise is effectively amplified by an injection of weak chaotic laser, and the g(2)(0) of the amplified quantum noise is measured with a real-time sample rate of 1.4 GHz. We also exploit a photon correlation convolutional neural network accelerating correlation data using a few quadrature fluctuations to perform a parallel processing of g(2)(0) for various chaos injection intensities and effective bandwidths. The deep-learning method accelerates the g(2)(0) experimental acquisition with a high accuracy, estimating 6107 sets of photon correlation data with a mean square error of 0.002 in 22 s and achieving a three orders of magnitude acceleration in the data acquisition time. This technique contributes to a high-speed and precision coherence evaluation of entropy source in secure communication and quantum imaging.

Breakthrough the physical barrier on spatial resolution in Raman distributed fiber sensing using chaotic correlation demodulation

Raman distributed optical fiber temperature sensors possess the unique capability of measuring spatial environmental temperatures, which can be of great interest in several fields of application. The key physics barrier to spatial resolution for most optical time-domain reflection (OTDR) systems is the positioning principle of pulse-time-flight. It obtains the spatial resolution of the existing Raman distributed optical fiber temperature sensor, with the kilometer-level sensing distance being limited to the meter-level. Here, we propose a chaotic laser Raman distributed optical fiber temperature sensing scheme that replaces the traditional OTDR positioning principle used for more than 40 years with the chaotic correlation positioning principle. The proposed scheme possesses the characteristics of the chaos Raman scattering light excited by the chaos signal along the sensing fiber. A novel measurement mechanism based on chaotic time-domain differential reconstruction and chaotic correlation demodulation is developed, and a relationship between the temperature variation information and the chaotic correlation peak is experimentally demonstrated. Importantly, the proposed optics mechanism scheme overcomes the physics limitation of the effect of a wide pulse width on sensing spatial resolution; its spatial resolution is optimized from 50 to 0.3 m under the modulation of a 500 ns pulse width. This scheme provides a new concept for chaos optics and fiber sensing research.

Rogue wave generation using a chaotic semiconductor laser with energy redistribution.

We demonstrate for the first time that optical rogue waves (RWs) can be generated using a chaotic semiconductor laser with energy redistribution. Chaotic dynamics are numerically generated using the rate equation model of an optically injected laser. The chaotic emission is then sent to an energy redistribution module (ERM) that consists of a temporal phase modulation and a dispersive propagation. The process enables a temporal energy redistribution of the chaotic emission waveforms, where coherent summation of consecutive laser pulses leads to random generation of giant intensity pulses. Efficient generation of optical RWs are numerically demonstrated by varying the ERM operating parameters in the entire injection parameter space. The effects of the laser spontaneous emission noise on the generation of RWs are further investigated. The RW generation approach offers a relatively high flexibility and tolerance in the choice of ERM parameters according to the simulation results.

Analysis of 4-Dimensional Caputo–Fabrizio Derivative for Chaotic Laser System: Boundedness, Dynamics of the System, Existence and Uniqueness of Solutions

Analysis of 4-Dimensional Caputo–Fabrizio Derivative for Chaotic Laser System: Boundedness, Dynamics of the System, Existence and Uniqueness of Solutions

Evolution of the time delay signature of chaos generated in three types of optical injection systems.

The time delay signature (TDS) of chaos generated in three schemes of optical injection has been investigated, and the mechanism of TDS suppression (TDSS) is revealed. The first scheme is a continuous-wave (CW) laser unidirectionally injecting into a chaotic laser, and the TDS of the chaotic laser is suppressed below 0.08 in this structure. The second scheme is a chaotic laser unidirectionally injecting into a CW laser, where the parameter range of TDSS lower than 0.06 of this structure is the largest among the three schemes. The third scheme is two CW lasers coupling to each other, and two chaotic lasers with TDS (T D S<0.1) suppression can be obtained simultaneously. For the further analysis of the mechanism of TDSS, the quasi-linear relationship between the synchronization coefficient and TDS is revealed. This study will provide insight into the generation of chaotic lasers by optical injection and promote the application of chaotic lasers.