5PMNOTH2 : THz Optoelectronics - WPMNDOT9

Goal(s)

The objective of this course is to address the generation of electromagnetic signals with frequencies between 100 GHz and 10 THz. The chosen approach is the generation of short electromagnetic pulses using a femtosecond laser emitting in the near infrared (IR) region.
We will therefore review in detail the characteristics of a short optical pulse (duration, spectrum, frequency drift), its propagation in dispersive media, and the possibilities of lengthening or compressing these pulses. We will then present the principles useful for obtaining such pulses (mode-locked laser) and their characterization (optical autocorrelation).
Next, continuing the course on semiconductor optics presented at the beginning of the semester, we will study in detail the generation of short electrical pulses by photoswitching an IR pulse. The signals thus obtained are short (1 ps duration) and broadband. We will review several of their applications, such as THz spectroscopy, which can be useful in many areas of physics (spectroscopy of gases, dense materials, optical studies, very high-speed wireless information transmission, imaging, etc.).

Content(s)

• Introduction (0h30)
• Chapter 1: Short Optical Pulses: Characteristics, Propagation (2h30)
• Chapter 2: Pulsed Optical Sources (1h30)
• Chapter 3: Characterization of Femtosecond Optical Pulses (1h30)
• Chapter 4: Generation and Detection of THz Electrical Signals (3h)
• Chapter 5: Applications (3h)

Introduction to Maxwell's equations and wave propagation.
Semiconductor Optics Course (Semester 5)
Laser Course

Test

Supervised homework on the table

Additional Information

Bibliography

Optoélectronique térahertz, J-L Coutaz et al. EDP Sciences, 2008.
Ultrashort Laser Pulse Phenomenon: Fundamentals, Techniques, and Applications on a Femtosecond Time Scale. J. C. Diels et W. Rudolph, Elsevier/Academic Press, 2006.
Ultrafast Optics, A. Wiener, Wiley, 2009.