Infotech Oulu Doctoral Program
Physical foundations and principles of semiconductor optoelectronics
Electronics laboratory organizes a post graduate course on OPTOELECTRONICS during
16 - 20th of January 2012 (Monday - Friday).
The abstract of the course contents and detailed course program are below. The course will contain 20 h lectures and approximately 10 hours of CAD exercises.
Please send an email to Jan Nissinen (email@example.com) by Thursday the 12th of January.
The course will start on Monday the 16th of January at 9.15 o´clock in the seminar room TS107.
The course discusses the microscopic physical properties of semiconductors (bandstructure, doping, carrier distribution) and phenomena (light absorption, emission, and refraction, photogeneration, electrooptic effects, waveguiding) which underpin the operation of semiconductor optoelectronic components.
Operating principles and main characteristics of semiconductor optoelectronic devices (lasers, amplifiers, modulators, photodetectors and solar cells) are discussed, some design examples presented, and some modern trends in semiconductor optoelectronics (high-density optoelectronic integration, single frequency and high power lasers) introduced.
Detailed course program
5 days, in each day 6 hours – 2×2 hours of lectures, 2×1 hours of practicals
Each 2-hour lecture to be followed by a 1-hour practical.
Lecture 1 (day 1 am)
- Conduction and valence bands in semiconductors
- Shallow donor and acceptor impurities in semiconductors
- Equilibrium carriers in semiconductors-1
- Equilibrium carriers in semiconductors-2 (compensation)
- Electron and hole statistics in semiconductors
- Determination of Fermi levels in semiconductors
- Energy band structure of semiconductor. Valence band structure.
Lecture 2. (day 1 pm)
- Absorption in semiconductors (phenomenology)
- Fundamental absorption: energy conservation law.
- Direct fundamental absorption-momentum conservation law
- Indirect fundamental absorption-momentum conservation law
- Electron-hole Coulomb attraction and direct fundamental absorption.
Excitonic effects in absorption
- Intervalence absorption-conservation laws
- Impurity absorption: conservation laws
- Equilibrium carrier band filling and absorption coefficient.
- Nonequilibrium carrier band filling and gain coefficient
Lecture 3. (day 2 am)
- Drift and diffusion of carriers in semiconductors.
- Poisson and Continuity equations
- p-n- junction formation. Space charge region.
- p-n-junction under forward bias. Minority carrier injection.
- p-n-junction under reverse bias.
- Semiconductor heterojunction formation.
- P-n and N-p-heterojunctions under forward bias.
- P-n and N-p-heterojunctions. Minority carriers injection.
- Double heterostructure. Forward and reverse bias. Basics of optical emission in a double heterostructure
Lecture 4. (day 2 pm)
- Heterostructure Quantum Wells.
- Density of states in Quantum Wells
- Carrier statistics in Quantum Wells.
- Light absorption and gain in Quantum wells.
- Quantum wires and dots: the ideal situation.
- Quantum dashes and dots. Inhomogeneous and homogeneous broadening.
- Carriers in quantum dashes and dots. Capture and excape processes.
- Absorption and gain in quantum dashes and dots.
Lecture 5. (day 3 am)
- Optical generation of nonequilibrium carriers in semiconductors. Linear and quandratic recombination cases.
- Absorption saturation in semiconductors (all-optical mechanisms)
- Photoconductivity caused by impurity phototransitions
- Photoconductivity caused by fundamental phototransitions (photoconductive gain )
- Photoconductive photodetectors.
- p-n-junction under illumination (photodiode)
- The main equation of the photodiode
- Solar cells
- P-i(n0)-N-heterostructure in the solar cell regime
- P-i(n0)-N -heterostructure in the photodiode regime
- Metal-semiconductor photodetectors
- 4.Resonant cavity enhanced photodetectors.
- Travelling-wave waveguide photodetector
Lecture 6. (day 3 pm)
- Electroabsorption in direct gap bulk semiconductors( Franz-Keldysh effect in direct gap semiconductors).
- Electroabsorption in direct gap bulk semiconductors ( Field ionization of exciton effect).
- Absorption due to fluctuation of impurity distribution.
- The reverse Franz-Keldysh effect: light emission under tunneling in electric field.
- Electroabsorption in semiconductors. The Quantum-Confined-Stark Effect (QCSE).
- Surface normal electroabsorption semiconductor modulators
- Electroabsorption in semiconductors and absorption saturation
- Negative resistance at electroabsorption in semiconductors.
- Self-Electrooptic Effect Devices (SEEDs).
Lecture 7 (day 4 am)
- Absorption/gain and refractive index in semiconductors. Kramers-Kronig relations. Relation between bandgap and refractive index.
- Semiconductor waveguides. Modal structure. Single-mode and multimode waveguides.
- Planar and stripe waveguides.
- Photonic nanowires.
- Foundations of silicon photonics and nanophotonics.
- Example of integrated photonic circuits (passive).
- Basics of photonic crystals as alternative integration platform
Lecture 8. (day 4 pm)
- Edge Emitting Semiconductor Lasers ( introduction).
- Basic structure of a Fabry-Perot laser diode
- Optical confinement (waveguide) in laser diode
- Lasing condition.
- Rate equations
- Output power and efficiency of semiconductor lasers
- Near field and far field patterns.
- Basic characteristics of laser diodes (emission spectra, light-current curves).
Lecture 9. (day 5 am)
- Single-frequency lasers: Distributed feedback (DFB)
- Distributed Bragg Reflector (DBR)
- Single-frequency lasers: VCSEL’s
- Single-frequency lasers: coupled cavity and discrete mode constructions.
- Transient phenomena (relaxation oscillations) and direct modulation
- Henry factor and Сhirp
- Direct and external modulation.
- High power semiconductor lasers.
- Example of high power laser design: high power broadened symmetric and narrow asymmetric lasers
Lecture 10. (day 5 pm)
- Semiconductor amplifiers: the operating principle.
- Amplified spontaneous emission.
- Gain and gain saturation in semiconductor amplifiers
- Patterning and the physics behind it. The role of the gain curve and spectral position. Quantum Dot amplifiers.
- SOAs in an interferometric configuration.
- Examples of optical integrated schemes involving active componens – lasers and amplifiers.
More information: Juha Kostamoraara
Last updated: 20.8.2012