The 3rd edition of Microcavities, by Alexey Kavokin, Jeremy J. Baumberg, Guillaume Malpuech and Fabrice P. Laussy, is in preparation for Oxford University Press.

TOC

From the working draft as of 14 October (2026):

§1 Overview of Microcavities

1. Introduction
2. Properties of microcavities
   1. $Q$-factor and finesse
   2. Intracavity field enhancement and field distribution
   3. Tuneability and mode separation
   4. Angular mode pattern
   5. Low-threshold lasing
   6. Purcell factor and lifetimes
   7. Strong vs. weak coupling
3. Microcavity realisations
4. Planar microcavities
   1. Metal microcavities
   2. Dielectric Bragg mirrors
5. Spherical mirror microcavities
6. Pillar microcavities
7. Bull's eye microcavities
8. Whispering-gallery modes
   1. Two-dimensional whispering galleries
   2. Three-dimensional whispering-galleries
   3. Toroidal microcavities
9. Photonic-crystal cavities
   1. Random lasers
10. Alternative materials for polaritonics
    1. GaN microcavities
    2. ZnO microcavities
    3. Organic microcavities
    4. Plasmonic nanocavities
    5. Perovskite cavities
    6. Liquid crystal cavities
    7. 2D-material cavities
11. Waveguide polaritonics
12. Optomechanical microcavities
13. Beyond microcavities
14. Conclusions
15. Further reading

§2 Classical description of light

1. Introduction
2. Free space
   1. Light-field dynamics in free space
   2. Polarisation
3. Propagation in crystals
   1. Plane waves in bulk crystals
   2. Absorption of light
   3. Kramers–Kronig relations
4. Singular optics
   1. Optical vortices
   2. Lemons and monstars
   3. Exceptional and diabolical points
5. Coherence
   1. Statistical properties of light
   2. Spatial and temporal coherence
   3. Wiener–Khinchin theorem
   4. Hanbury Brown–Twiss effect
6. Polarisation-dependent optical effects
   1. Birefringence
   2. Magneto-optical effects
7. Propagation of light in multilayer planar structures
8. Photonic eigenmodes of planar systems
   1. Photonic bands of 1D periodic structures
9. Planar microcavities
10. Tamm plasmons and photonic Tamm states
11. Stripes, pillars and spheres: photonic wires and dots
    1. Cylinders and pillar cavities
    2. Spheres
12. Conclusions
13. Further reading

§3 Quantum description of light

1. Introduction
2. Pictures of quantum mechanics
   1. Historical background
   2. Schrödinger picture
   3. Antisymmetry of the wavefunction
   4. Symmetry of the wavefunction
   5. Heisenberg picture
   6. Dirac (interaction) picture
3. Other formulations
   1. Density matrix and Liouvillian
   2. Second quantisation
   3. Quantisation of the light field
4. Quantum states
   1. Fock and coherent states
   2. Representations of states
   3. Gaussian and non-Gaussian states
   4. Thermal and mixed states
   5. Quantum states correlations
   6. Quantum states dynamics
   7. Quantum states in space and time
5. Symmetries of quantum mechanics
   1. Translational and rotational symmetry of space
   2. Antisymmetry of the wavefunction
   3. Symmetry of the wavefunction
   4. Gauge symmetry
6. Two-level/band systems and the effective field representation
7. Geometric quantum tensor
   1. Quantum metric and Berry curvature
   2. The peculiar case of two-band systems
8. Conclusions
9. Further reading

§4 Semiclassical description of light–matter coupling

1. Introduction
2. Light–matter interaction
   1. Classical limit
   2. Einstein coefficients
3. Optical transitions in semiconductors
4. Excitons in semiconductors
   1. Frenkel and Wannier–Mott excitons
   2. Excitons in confined systems
   3. Quantum wells
   4. Quantum wires and dots
5. Exciton–photon coupling
   1. Surface polaritons
   2. Exciton–photon coupling in quantum wells
   3. Exciton–photon coupling in quantum wires and dots
   4. Dispersion of polaritons in planar microcavities
   5. Motional narrowing of cavity polaritons
   6. Microcavities with quantum wires or dots
   7. Rydberg polaritons
6. Conclusions
7. Further reading

§5 Quantum description of light–matter coupling

1. Introduction
2. Rabi dynamics
3. Bloch equations
4. Full quantum picture
   1. Light–matter interaction Hamiltonian
   2. Dressed bosons
   3. Josephson coupling
   4. Jaynes–Cummings model
   5. Dicke model
5. Lindblad dissipation
6. Quantum dynamics with decay and pumping
   1. Single-time dynamics of coupled Bose fields
   2. Two-time dynamics of coupled Bose fields
   3. The two-level system coupled to a Bose field
7. Excitons in semiconductors
   1. Quantisation of the exciton field
   2. Excitons as bosons
   3. Excitons in quantum dots
8. Exciton–photon coupling
   1. Polariton splitting
   2. The polariton Hamiltonian
9. Conclusions
10. Further reading

§6 Weak-coupling microcavities

1. Introduction
2. Purcell effect
   1. The physics of weak coupling
   2. Spontaneous emission
   3. Quantum dots, 2D excitons and 2D electron–hole pairs
   4. Fermi's golden rule
   5. Dynamics of the Purcell effect
   6. Experimental realisations
   7. Purcell effect in photonic-crystal and plasmonic cavities
3. Lasers
   1. The physics of lasers
   2. Semiconductors in laser physics
   3. Vertical-cavity surface-emitting lasers
   4. Resonant-cavity LEDs
   5. Quantum theory of the laser
   6. Microcavity lasers
4. Nonlinear optical properties of weak-coupling microcavities
   1. Bistability
   2. Phase matching
5. Conclusions
6. Further reading

§7 Strong coupling: resonant effects

1. Introduction
2. Optical properties: background
   1. Quantum well microcavities
   2. Variations on a theme
   3. Motional narrowing
   4. Ultra-strong coupling in THz cavities
   5. Polariton emission
3. Near-resonant-pumped optical nonlinearities
   1. Pulsed stimulated scattering
   2. Quasimode theory of parametric amplification
   3. Microcavity parametric oscillators
4. Resonant excitation case and parametric amplification
   1. Semiclassical description
   2. Stationary solution and threshold
   3. Theoretical approach: quantum model
   4. Three-level model
   5. Threshold
5. Two-beam experiment
   1. One-beam experiment and spontaneous symmetry breaking
   2. Dressing of the dispersion induced by polariton condensates
   3. Bistable behaviour
6. Propagation of polaritons
   1. Polariton wavepackets
   2. Self-accelerating and self-interfering wavepackets
   3. Rabi-oscillating vortex (Rartex)
   4. Superfluid propagation
   5. Elementary excitation of resonantly pumped polaritons
   6. Polariton turbulence
   7. Conventional and unconventional polariton superfluidity
   8. High-density effects: the polariton backjet
7. Conclusions
8. Further reading

§8 Strong coupling: polariton Bose condensation

1. Introduction
2. Basic ideas about Bose–Einstein condensation
   1. Einstein proposal
   2. Experimental realisation
   3. Modern definition of Bose–Einstein condensation
3. Specificities of excitons and polaritons
   1. Thermodynamic properties of cavity polaritons
   2. Interacting bosons and Bogoliubov model
   3. Polariton superfluidity
   4. Quasicondensation and local effects
4. Kinetics of formation of polariton condensates: semiclassical picture
   1. Qualitative features
   2. The semiclassical Boltzmann equation
   3. Numerical solution of Boltzmann equations: practical aspects
   4. Effective scattering rates
   5. From thermodynamic to kinetic regime
5. Kinetics of formation of polariton condensates: quantum picture in the Born–Markov approximation
   1. Density matrix dynamics of the ground state
   2. Discussion
   3. Coherence dynamics
6. Kinetics of formation of polariton condensates: quantum picture beyond the Born–Markov approximation
   1. Two-oscillator toy theory
   2. Coherence of polariton laser emission
   3. Truncated Wigner approximation
   4. Numerical simulations
   5. Order parameter and phase diffusion coefficient
   6. $\alpha$-coherence
7. Spatial dynamics of polariton condensates
   1. Polariton billiard
   2. Gross–Pitaevskii equation
   3. Modified Gross–Pitaevskii equations
   4. Reservoir–condensate coupling
   5. Bogolon dispersion
   6. Spatial coherence. The thermal fluctuation effect
   7. Topological order and thermal equilibrium
8. Experiments on Bose–Einstein condensation, superfluidity and lasing of polaritons
   1. Experimental observation
   2. Polariton lasing vs Bose–Einstein condensation
   3. Polariton diodes
   4. Experiments on superfluidity
9. Superconductivity mediated by light, excitons and polaritons
10. Conclusions
11. Further reading

§9 Spin and polarisation

1. Introduction
2. Photonic modes in planar microcavities
   1. Transverse Electric-Transverse Magnetic modes and photonic spin-orbit coupling
   2. Pseudo-spin representation
   3. Fabry-Perot cavities
3. Emulation of topological singularities: from parabolic band touching to Dirac points
   1. Linear birefringence
   2. Tilted Dirac points
   3. Rashba-Dresselhaus spin-orbit coupling (RDSOC)
   4. Mass anisotropy
   5. Zeeman splitting
   6. Summary
4. Quantum Geometric tensor and basic elements of topology
5. Non-Hermiticity
   1. Exceptional points (EPs)
   2. Bound state in the continuum (BIC)
6. Spin relaxation of electrons, holes and excitons in semiconductors
7. Microcavities in the presence of a magnetic field
8. Resonant Faraday rotation
9. Spin relaxation of exciton-polaritons in microcavities: experiment
10. Spin relaxation of exciton-polaritons in microcavities: theory
11. Optical spin Hall effect
12. Full Poincaré beams and polarisation shaping in microcavities
13. Optically-induced Faraday rotation
14. Interplay between spin and energy relaxation of exciton-polaritons
15. Polarisation of Bose condensates and polariton superfluids
16. Magnetic-field effect and superfluidity
17. Finite temperature case
18. Stationary states of spinor condensates
19. Semi-classical theory of transport in topologically non-trivial bands
    1. Adiabatic limit and the Anomalous Hall effect
    2. Coherent spin-space dynamics: Zitterbewegung and Non-Abelian Gauge field
    3. Unified semi-classical equation based on the quantum metric
20. Conclusions
21. Further reading

§10 Quantum fluids of light

1. Introduction
2. Topological excitations in quantum fluids of light
   1. Topological defects in scalar condensates
   2. Interaction with a static defect; superfluidity and topology
3. Half-integer topological defects in spinor quantum fluids
   1. Introduction
   2. Half-vortices
   3. Half-solitons
4. Hydrodynamic generation of oblique half-solitons and half-vortices
5. Spin bifurcation theory (broken parity)
   1. Paramagnetic solutions.
   2. Ferromagnetic solutions.
6. Exotic polaritonic phases
   1. Bound state in the continuum
   2. Time crystal
   3. Supersolid
   4. Polariton black hole
7. Phase transitions in open quantum systems
8. Conclusions
9. Further reading

§11 Synthetic polaritonic matter

1. Introduction
2. Lattice implementations in microcavities
   1. Engineering of the polariton band structure
   2. Wire cavities
   3. Single pillars and molecules
   4. A few basics about 1D lattices
   5. Bright- and gap-solitons in 1D polariton systems
   6. Honeycomb lattice (scalar approximation)
   7. Honeycomb lattice (polarised)
3. Photonic and polaritonic topological insulators
   1. Concept of topological insulators
   2. Intrinsic chirality of photons
   3. $\mathbb{\mathbb{Z}}$ and ${\mathbb{\mathbb{Z}}}_2$ polaritonic topological insulators
   4. Polariton topological insulators
4. Interacting quantum fluids in topologically non-trivial bands
5. Topological lasers
6. Conclusions
7. Further reading

§12 Quantum polaritonics

1. Introduction
2. Microcavity QED
   1. Quantum vs classical polaritons
   2. Control of polariton Rabi oscillations
   3. Polariton squeezing
   4. Polariton statistics
   5. Polariton entanglement
3. Polariton blockade
   1. Jaynes–Cummings blockade
   2. Kerr blockade
   3. Unconventional blockade
   4. The CU/BA picture
4. Frequency-resolved photon correlations
   1. Photo-detection theory
   2. The sensor method
   3. Two-photon spectra
   4. Frequency-resolved quantum Monte Carlo
5. $N$–photon emitters
   1. Multiphoton emission from the $N$-level system
   2. Super-Rabi oscillations
   3. Robust Jaynes–Cummings resonances
   4. Bundles of photons
6. Exciting with quantum light
   1. Cascaded formalism
   2. Exciting simple targets
   3. Mollow spectroscopy
7. Quantum information processing
   1. Quantum computation
   2. Limits of quantum computation
   3. Quantum annealing
   4. Polariton simulator
   5. Polariton qubits and cebits
   6. Other paradigms
8. Debate about quantumness
9. Conclusions
10. Further reading

§13 Polariton devices

1. Introduction
2. Polariton lasers
   1. Concept of polariton lasing
   2. Realisation of polariton lasers in semiconductor microcavities
3. Polariton lasers with electrical injection
   1. Experimental manifestations
   2. Weak lasing
4. Polariton terahertz lasers
   1. Variety of proposals
   2. Polariton terahertz lasers with two-photon excitation
   3. Superradiant emission of terahertz radiation by dipolaritons
5. Bosonic cascade lasers
   1. The Boltzmann dynamics of bosonic cascades
   2. Quantum model of a bosonic cascade laser
6. Spatial dynamics of polariton lasing structures
   1. Pattern formation
   2. Control of lasing modes in structured potentials
   3. Bistability and polariton condensate memories
   4. Polariton quantum random number generators
7. Polariton condensate transistors and optical circuits
   1. Polariton interferometers
   2. Polariton transistors
   3. Polariton neurons
   4. Polariton neural networks
8. The enigma of polariton simulators
   1. Experiments on polariton simulators and their interpretation
   2. Formation of multi-condensate modes
   3. Mapping to the XY-model
   4. Phase locking in polariton arrays
   5. Scaling and decoherence
   6. Conclusions
9. Conclusions
10. Further reading