Photonics & Microwave Transmitters & Receivers

The course associated with this unit aims to provide students with a comprehensive understanding of photonic and microwave transmitters and receivers, ranging 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 analogies between these two frequency domains. The targeted competencies therefore include knowledge of the operation and main characteristics of these active, optical, and microwave components, which are essential for the development of telecommunications systems, sensors, radars, and more.

This teaching unit has several objectives:

• Basic concepts in the fabrication of semiconductor structures; understanding of the physical principles underlying the operation of optoelectronic and microwave components.
• Understand the main applications of optoelectronic and microwave components.
• Understand how optical and microwave amplifiers and oscillators work, and be familiar with their main characteristics in order to select 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 Assessment

Optical amplifiers

1. Introduction: Why Amplify?
2. Wave-Matter Interaction

• Wave Aspects (Lorentz Model) & Particle Aspects
• Effective sections
• Uniform and Non-Uniform Widths

1. Fiber-optic amplifiers

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

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

1. Introduction to Solid-State Amplifiers

Lasers

1. Introduction & History
2. Continuous-wave 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 with Spatial Hole Burning
• Frequency Attraction

1. Continuous-Wave Laser Dynamics

• Evolution Equations
• Classes of Laser Dynamics
• Multimodal Dynamics (Lyapunov Coefficients)

1. Spatial and Temporal Coherence: Definition, Measurement, and Quantitative Measures
2. How Pulsed Lasers Work:

• Maintainedspiking lasers
• Q-switched lasers
• Mode-locked lasers

1. The Zoology of Lasers
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. Applications of Semiconductor Lasers

Microwave Components 

1. Review 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
• Adaptability and Stability
• Winnings
• 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 Sensors 

1. Photometry
2. Visible area
3. Gain Detectors
4. IR Spectral Domain: Review of IR fundamentals: Planck’s law, spectral emissivity, atmospheric transmission window, thermal IR, SWIR, MWIR, LWIR, VLWIR, multispectral imaging, selection of spectral bands, thermal contrast criteria for imaging, orders of magnitude. IR photodetectors versus thermal detectors.
5. Key Performance Indicators for IR Detectors 
6. Fabrication and Characterization of an IR PD
7. IR Cameras

Noise

1. The Fundamental Nature of Noise
2. Shot Noise (optical and electronic) + other electronic noise
3. Photodetection and Noise
4. Noise in Oscillators
5. Noise in Amplifiers
6. Noise in Optoelectronic Systems

CM: 84 hours