Chaotic Lidar

Lin, Fan-Yi; Liu, J.-M.

doi:10.1109/jstqe.2004.835296

Cited by 353 publications

(108 citation statements)

References 31 publications

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“…For instance, macroscopic chaos serving directly as a masking carrier improves the rate of secure communications to gigabits per second [1]. Additionally, fast chaos replaces microscopic noise as an entropy source to greatly increase the speed of generating physical random keys [2,3] and as a radar signal to enhance anti-jamming capability and spatial resolution [4,5]. One of the most important factors is that the physical chaos has a spread spectrum and an irregular waveform with larger amplitude than that of microscopic noise, and the use of chaos can avoid the wideband amplification required in a noise generator.…”

mentioning

confidence: 99%

Optical Heterodyne Generation of High-Dimensional and Broadband White Chaos

Wang¹,

Wang²,

Li³

et al. 2015

IEEE J. Select. Topics Quantum Electron.

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Physical chaos is a fascinating prospect for high-speed data security by serving as a masking carrier or a key source, but suffers from a colored spectrum that divulges system's intrinsic oscillations and degrades randomness. Here, we demonstrate that physical chaos with a white spectrum can be achieved by the optical heterodyning of two delayed-feedback lasers. A white chaotic spectrum with 1-dB fluctuation in a band of 11 GHz is experimentally obtained. The white chaos also has a perfect delta-like autocorrelation function and a high dimensionality of greater than 10, which makes chaos reconstruction extremely difficult and thus improves security. PACS numbers: 42.65. Sf, 05.45.Jn Macroscopic chaos in fast nonlinear optoelectronic or laser systems has motivated remarkable developments in information security. For instance, macroscopic chaos serving directly as a masking carrier improves the rate of secure communications to gigabits per second [1]. Additionally, fast chaos replaces microscopic noise as an entropy source to greatly increase the speed of generating physical random keys [2,3] and as a radar signal to enhance anti-jamming capability and spatial resolution [4,5]. One of the most important factors is that the physical chaos has a spread spectrum and an irregular waveform with larger amplitude than that of microscopic noise, and the use of chaos can avoid the wideband amplification required in a noise generator.Essentially, the randomness and security of chaos is vital to chaos-based information security. However, the randomness of physical chaos is usually degraded by intrinsic oscillations of nonlinear chaos systems. Currently, fast physical chaos generators typically consist of a nonlinear optical or optoelectronic device subject to a feedback loop that partially couples the output back into the device, such as an external-cavity semiconductor laser (ECL) [6] and an optoelectronic oscillator [7]. As a result, the intrinsic oscillations, including the characteristic response frequency of the nonlinear device and the resonance of the feedback loop, introduce deterministic features and periodicity into the chaos and thus limit the randomness. Taking the paradigm of a delay system, i.e., an ECL, as an example, the relaxation oscillation of the semiconductor laser dominates the laser intensity chaos and leads to a strong peak projecting from the power spectrum [8]. Additionally, the resonance of the external feedback cavity excites many external-cavity modes (ECMs) in the laser field and leads to a periodically modulated spectrum similar to that of a frequency comb with a spacing equal to the reciprocal of the feedback delay [9,10]. Considerable effort has recently been devoted to expand the power spectrum [8,11] or to depress the external-cavity resonances [12], but it is difficult to completely eliminate the effects of the intrinsic oscillations [3,13]. These intrinsic oscillations impose restrictions on random number generation from physical chaos [10] and raise arguments that the extracted number...

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confidence: 99%

Optical Heterodyne Generation of High-Dimensional and Broadband White Chaos

Wang¹,

Wang²,

Li³

et al. 2015

IEEE J. Select. Topics Quantum Electron.

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“…Chaos can be generated in laser band rather easily, and the laser based chaotic radar system, along with its ambiguity functions, has been exploited [8,15,16]. Regarding the microwave chaotic signals, it is not until recent years that chaotic circuits with fundamental frequency more than 1 GHz were implemented [17][18][19], where the Colpitts oscillator is the major candidate due to its simple circuit structure.…”

Section: Introductionmentioning

confidence: 99%

Ambiguity Functions of Direct Chaotic Radar Employing Microwave Chaotic Colpitts Oscillator

Shi¹,

Qiao²,

Chen³

et al. 2007

PIER

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Abstract-The ambiguity functions of a kind of direct chaotic radar system are investigated. In this radar system, a microwave chaotic Colpitts oscillator is employed to generate the source signal that is directly transmitted through a wideband antenna without modulation. The auto-ambiguity function of this radar system shows many sidelobes which makes the unambiguous detection difficult. It is because the spectrum of the chaotic signal is not very flat and smooth, with pulsation peaks in it. The cross-ambiguity functions of the direct radar system have also been investigated to evaluate the electronic counter countermeasure (ECCM) performance and the "multi-user" characteristic. It is shown that rather excellent ECCM capability can be achieved in this radar system with transmitting chaotic signals generated by circuits with same parameters but at different time or with slightly different circuit parameters. In addition, several possible methods to reshape the spectrum of the chaotic signal from microwave Colpitts oscillators to improve the unambiguous detection performance are suggested at the end of this paper.

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“…As a method that does not need a high-power output and a highspeed modulation, a chaotic Lidar has been reported. [8][9][10] It utilizes a chaotic intensity signal generated by the optical feedback to a semiconductor laser. However, due to the feedback condition, the oscillation state also changes to a state other than chaos.…”

mentioning

confidence: 99%

Study on the resolution improvement of a range finder using the chaotic frequency characteristics of a laser diode

et al. 2017

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Study on the resolution improvement of a range finder using the chaotic frequency characteristics of a laser diode," Opt. Eng. 56(6), 064101 (2017), doi: 10.1117/1.OE.56.6.064101. Abstract. An optical range finder system that relies on laser diodes' frequency noise, instead of intensity or frequency modulations, and its improvement in resolution are reported. The distance to the target is measured by calculating the cross-correlation of two signals reflected from the target and reference mirrors. These two signals are converted from the laser diodes' frequency noise signals by frequency/intensity converters, such as a Fabry-Perot etalon. We obtained the distance to the target by checking time lags between the target and reference beams at the highest correlation coefficient. We also measured the change in the correlation coefficient around the peak sampling point by adjusting the reference-path length, achieving a resolving power of AE3 mm. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Chaotic Lidar

Cited by 353 publications

References 31 publications

Optical Heterodyne Generation of High-Dimensional and Broadband White Chaos

Optical Heterodyne Generation of High-Dimensional and Broadband White Chaos

Ambiguity Functions of Direct Chaotic Radar Employing Microwave Chaotic Colpitts Oscillator

Study on the resolution improvement of a range finder using the chaotic frequency characteristics of a laser diode

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