THz Optoelectronics - 5PMNOTH2

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).
We 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 then present the principles useful to obtain such pulses (mode-locked laser) and to characterize them (optical autocorrelation).
Then, following the course on semiconductor optics given at the beginning of the semester, we will study in detail the generation of short electrical pulses by photocommutation of an IR pulse. The resulting signals 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 transmissions, imaging etc...).

Content(s)

• Introduction (0h30)
• Chapter 1: Short optical pulses: characteristics, propagation (2h30)
• Chapter 2: Optical pulse sources (1h30)
• Chapter 3: Characterization of femtosecond optical pulses (1h30)
• Chapter 4: Generation and detection of THz electrical signals(3 h)
• Chapter 5: Applications(3h)

Notions on Maxwell's equations and wave propagation.
Semiconductor Optics
Course on lasers