Photonic & Microwave Transmitters & Receivers

The program associated with this EU offers students a comprehensive overview of photonic and microwave transmitters and receivers, from materials physics to active components and their packaging. Microwave amplifiers and oscillators will be covered alongside optical amplifiers and lasers in order to highlight the obvious similarities between these two frequency ranges. The skills targeted are therefore knowledge of the operation and main characteristics of these active, optical, and microwave components, which are essential in the development of telecommunications systems, sensors, radars, etc.

The objectives of this EU are multiple:

• Basic knowledge of semiconductor structure manufacturing, understanding of the physical principles behind the operation of optoelectronic and microwave components.
• Know the main applications of optoelectronic and microwave components.
• Understanding how optical and microwave amplifiers and oscillators work, knowing their main characteristics in order to be able to choose or use them appropriately in more complex systems.

Fundamentals of semiconductor physics, S-parameters, propagation in free space and guided media (particularly microwave lines), diffraction, and interference

Recommended prerequisites:

Fundamentals of electromagnetism.

Continuous Monitoring

Optical amplifiers

1. Introduction: why amplify
2. Wave-Matter Interaction

• Wave aspect (Lorentz model) & particle aspect
• Effective sections
• Homogeneous and inhomogeneous widths

1. Fiber optic amplifiers

• Amplification in active fibers
• 2-, 3-, or 4-level systems
• Detailed study of a 3-level system:

Gain, population inversion, gain saturation by the pump and the signal

1. Introduction to Solid-State Amplifiers

Lasers

1. Introduction & history
2. Continuous laser oscillation

• Fabry-Perot cavity with gain and losses: conditions for the laser effect (amplitude and phase)
• Laser power and gain locking
• Spectral properties of a homogeneous/inhomogeneous gain laser, spatial hole burning
• Frequency attraction

1. Continuous laser dynamics

• Evolution equations
• Laser dynamics classes
• Multimodal dynamics (Lyapunov coefficients)

1. Spatial and temporal coherence: definition, measurement, and quantitative measures
2. How pulsed lasers work:

• Maintained oscillating lasers (spiking)
• Q-switched lasers
• Mode-locked lasers

1. Laser Zoology
2. Laser safety

Materials / Semiconductor lasers 

1. Introduction
2. Semiconductors – structural properties
3. Semiconductors – electronic properties
4. Lasers
5. Semiconductor lasers
6. Electro-optical characterization of semiconductor lasers
7. Application of semiconductor lasers

Microwave components 

1. Reminders of semiconductor physics
2. Microwave diodes

• 1. PN diode
• 2. PIN diode
• 3. Gunn diode
• 4. Schottky diode
• 5. Tunnel Diode
• 6. Avalanche diode

1. Microwave transistors

• 1. Bipolar transistor (BJT, HBT)
• 2. Field-effect transistor (MESFET, HEMT)

1. Microwave applications

• 1. Receivers
• 2. Transmitters

Microwave amplifiers and oscillators

1. Amplifier

• Transistor-based design
• Transistor stability
• Adaptation and stability
• Gains
• Amplifier noise
• Wideband amplifier
• Power amplifier

1. Microwave oscillators

• Features
• Low-frequency oscillators
  • Oscillation conditions
  • Stabilization
  • L and C-based circuits
  • Quartz oscillators
• Microwave Oscillators
  • Oscillation conditions
  • Diode oscillators
  • Transistor oscillators
  • Resonant dielectric oscillators
• Variable frequency oscillators
• High-power amplifiers and oscillators

Visible and IR optical detectors 

1. Photometry
2. Visible domain
3. Gain detectors
4. IR spectral range: IR background information: Planck's law, spectral emissivity, atmospheric transmission window, SWIR, MWIR, LWIR, VLWIR thermal IR, multispectrality, choice of spectral bands, thermal contrast criteria for imaging, orders of magnitude. IR photodetectors versus thermodetectors.
5. The merits of IR detectors 
6. Fabrication and characterization of an IR PD
7. IR cameras

Noise

1. Fundamental nature of noise
2. Shot Noise (optics and electronics) + other electronic noise
3. Photodetection and Noise
4. Noise in oscillators
5. Noise in amplifiers
6. Noise in optoelectronic systems

CM: 84 hours