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: Hardback
Length: 166 pages
Publication date: 16 May 2021
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 fingerprints of numerous chemical compounds can be detected in this spectral range. Among the available sources in the MIR domain, quantum cascade lasers (QCLs) have emerged as highly valuable tools for spectroscopic purposes and free-space communications.

In this thesis, we explore the implementation of private free-space communication utilizing mid-infrared optical chaos. To achieve this, we must accurately map out the intricate non-linear phenomena present in QCLs. By synchronizing the chaotic behavior of two twin QCLs, we enable private transmission through the chaotic synchronization process.

QCLs can generate chaos 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, in addition to chaos. When the chaotic dropouts in QCLs are synchronized with an external modulation, a phenomenon known as entrainment occurs. This effect is similar to what happens in laser diodes when chaotic dropouts are entrained. By employing a cross-polarization reinjection technique, QCLs can generate all-optical square waves. Furthermore, it is possible to trigger optical extreme events in QCLs by employing tilted optical feedback.

These experimental findings provide valuable insights into the non-linear dynamics of QCLs, expanding their potential applications in various fields. The study of MIR optics continues to evolve, offering exciting opportunities for researchers and industry professionals alike.

Weight: 454g
Dimension: 235 x 155 (mm)
ISBN-13: 9783030743062
Edition number: 1st ed. 2021