Mid-infrared Quantum Cascade Lasers for Chaos Secure Communications

This thesis explores the use of quantum cascade lasers (QCLs) in private free-space communication, leveraging their ability to generate mid-infrared optical chaos. By accurately mapping non-linear phenomena in QCLs, chaos synchronization enables private transmission through the entrainment phenomenon. Additionally, all-optical square-waves and extreme optical events can be triggered, expanding the applications of QCLs in non-linear optics.

Format: Paperback / softback
Length: 166 pages
Publication date: 17 May 2022
Publisher: Springer Nature Switzerland AG

The mid-infrared (MIR) region holds immense potential as an optical domain, thanks to its unique characteristics. It boasts two transparency atmospheric windows, making it an ideal platform for various applications. Moreover, the MIR spectrum contains the distinctive fingerprints of numerous chemical compounds, making it a valuable tool in analytical and diagnostic sciences. Among the available sources in this domain, quantum cascade lasers (QCLs) stand out as highly promising. QCLs have already demonstrated their usefulness in spectroscopic applications and free-space communications.

In this thesis, we explore the implementation of private free-space communication using mid-infrared optical chaos. To achieve this, we require a comprehensive understanding of the non-linear phenomena present in QCLs. Chaos in QCLs can be generated through optical injection or external optical feedback. Depending on the specific parameters of the optical feedback, QCLs can exhibit a range of non-linear phenomena, including chaos, quasi-periodic oscillations, and bistability.

One fascinating phenomenon observed in QCLs is the entrainment phenomenon. When the chaotic dropouts in QCLs are synchronized with an external modulation, they exhibit similarities to laser diodes. This effect is known as the entrainment phenomenon, and it has significant implications for communication and signal processing applications.

QCLs also possess the ability to generate all-optical square waves through a cross-polarization reinjection technique. This technique involves injecting a polarized beam into the QCL and then applying a cross-polarization modulation to the injected beam. The resulting output is a square wave with high purity and coherence.

Furthermore, QCLs can be engineered to trigger optical extreme events, such as optical chaos and optical bistability, by manipulating the tilt of the optical feedback. These extreme events have potential applications in various fields, including optical data storage, optical communication, and optical sensing.

The experimental results presented in this thesis provide valuable insights into the non-linear dynamics of QCLs. By understanding these phenomena, we can further enhance the potential applications of QCLs in various fields, including spectroscopy, remote sensing, and communication.

In conclusion, the mid-infrared region holds immense potential for optical applications, and QCLs are one of the most promising sources in this domain. This thesis demonstrates the implementation of private free-space communication using mid-infrared optical chaos, and it highlights the importance of a comprehensive understanding of the non-linear phenomena present in QCLs. The experimental results presented herein pave the way for future advancements in optical technology and offer exciting opportunities for researchers and industry professionals.

Weight: 291g
Dimension: 235 x 155 (mm)
ISBN-13: 9783030743093
Edition number: 1st ed. 2021