Semiconductor Optoelectronics

This course introduces the students to the field of Semiconductor Optoelectronics, which deals with the physics and technology of semiconductor optoelectronic devices such as light emitting diodes, laser diodes and photodiodes, which are becoming important components in consumer optoelectronics, IT and communication devices, and in industrial instrumentation. Assuming a general science/engineering undergraduate level background, the course begins with a recap of essential (to this course) semiconductor physics, followed by the study of interaction of photons with electrons and holes in a semiconductor, leading to the realization of semiconductor photon amplifiers, sources, modulators, and detectors. A variety of designs and configurations of these devices have been emerging with application-specific characteristics. The course is ‘applied’ in nature, and could be offered at the level of B.E/B.Tech IIIrd/ IVth Year, M.Sc IInd/ M.Tech. I Year.

Context and Scope of the Course.
Energy Bands in Solids.
E-K Diagram.
The Density of States.
The Density of States (contd..).
The Density of states in a Quantum well Structure.
Occupation Probability and Carrier Concentration.
Carrier Concentration and Fermi Level.
Quasi Fermi Levels.
Semiconductor Materials.
Semiconductor Hetrostructures-Lattice-Matched Layers.
Strained -Layer Epitaxy and Quantum Well Structures.
Bandgap Engineering.
Hetrostructure p-n junctions.
Schottky Junction and Ohmic Contacts.
Fabrication of Heterostructure Devices.
Interaction od Photons with Electrons and Holes in a Semiconductor.
Optical Joint Density of States.
Rates of Emission and Absorption.
Amplication by Stimulated Emission.
The Semiconductor (Laser) Amplifier.
Absorption Spectrum of Semiconductor.
Gain and Absorption Spectrum of Quantum Well Structures.
Electro-absorption Modulator.
Electro-absorption Modulator - II Device Configuration.
Mid-Term Revision Question and Discussion.
Part - III Semiconductor Light Sources.
Light Emitting Diode-I Device Structure and Parameters.
Light Emitting Diode-II Device Chracteristics.
Light Emitting Diode-III Output Characteristics.
Light Emitting Diode-IV Modulation Bandwidth.
Light Emitting Diode-V materials and Applications.
Laser Basics.
Semiconductor Laser - I Device Structure.
Semiconductor Laser - II Output Characteristics.
Semiconductor Laser - III Single Frequency Lasers.
Vertical Cavity Surface Emitting Laser (VCSEL).
Quantum Well Laser.
Practical Laser Diodes and Handling.
General Characteristics of Photodetectors.
Responsivity and Impulse Response.
Photoconductors.
Semiconductor Photo-Diodes.
Semiconductor Photo-Diodes -II : APD.
Other Photodectors.
Photonic Integrated Circuits.