Polaritons before the cavity

The most famous and important type of polaritons is the Microcavity polariton, discovered serendipitously by Claude Weisbuch in 1992.

Describing his finding, he cites the following works:

Comparison of Quantum and Semiclassical Radiation Theory with Application to the Beam Maser. E.T. Jaynes and F.W. Cummings in Proc. IEEE 51:89 (1963).
Normal-mode splitting and linewidth averaging for two-state atoms in an optical cavity. M. G. Raizen, R. J. Thompson, R. J. Brecha, H. J. Kimble and H. J. Carmichael in Phys. Rev. Lett. 63:240 (1989).
Vacuum Rabi splitting as a feature of linear-dispersion theory: Analysis and experimental observations. Y. Zhu, D. J. Gauthier, S. E. Morin, Q. Wu, H. J. Carmichael and T. W. Mossberg in Phys. Rev. Lett. 64:2499 (1990).
Book chapter by Yamamoto & Modification of spontaneous emission rate in planar dielectric microcavity structures. G. Björk, S. Machida, Y. Yamamoto and K. Igeta in Phys. Rev. A 44:669 (1991).
Inhibited Spontaneous Emission in Solid-State Physics and Electronics. E. Yablonovitch in Phys. Rev. Lett. 58:2059 (1987). and Photonic Band Structure. E. Yablonovitch in Opt. Photonics News 2:27 (1991).
Analysis of semiconductor microcavity lasers using rate equations. G. Bjork and Y. Yamamoto in IEEE Quantum Electron. 27:2386 (1991).
«For a recent and exhaustive review, see S. Haroche, in Fundamental Systems in Quantum Optics, edited by J. Dalibard et al. (Elsevier, Amsterdam, 1992); see also» Cavity Quantum Electrodynamics. S. Haroche and D. Kleppner in Physics Today 42:24 (1989).
Enhanced spontaneous emission from GaAs quantum wells in monolithic microcavities. H. Yokoyama, K. Nishi, T. Anan, H. Yamada, S. D. Brorson and E. P. Ippen in Appl. Phys. Lett. 57:2814 (1990).
Enhanced and inhibited spontaneous emission in GaAs/AlGaAs vertical microcavity lasers with two kinds of quantum wells. T. Yamauchi, Y. Arakawa and M. Nishioka in Appl. Phys. Lett. 58:2339 (1991).
Theory of Spontaneous-Emission Line Shape in an Ideal Cavity. J. J. Sanchez-Mondragon, N. B. Narozhny and J. H. Eberly in Phys. Rev. Lett. 51:550 (1983).
Dynamic Stark effect of exciton and continuum states in CdS. N. Peyghambarian, S. Koch, M. Lindberg, B. Fluegel and M. Joffre in Phys. Rev. Lett. 62:1185 (1989).; Ultrafast adiabatic following in semiconductors. R. Binder, S. Koch, M. Lindberg, N. Peyghambarian and W. Schäfer in Phys. Rev. Lett. 65:899 (1990).; Femtosecond excitonic bleaching recovery in the optical Stark effect of GaAs/Al$_x$Ga$_{1-x}$As multiple quantum wells and directional couplers. S. Lee, P. Harten, J. Sokoloff, R. Jin, B. Fluegel, K. Meissner, C. Chuang, R. Binder, S. Koch, G. Khitrova, H. Gibbs, N. Peyghambarian, J. Polky and G. Pubanz in Phys. Rev. B 43:1719 (1991).
Cavity quantum electrodynamics in quantum well lasers. Y. Yamamoto, S. Machida and G. Björk in Surf. Sci. 267:605 (1992).
«See, e.g. , R. Knox, Theory of ExcitonsSolid , State Phys. (Academic, New York, 1963), Suppl. 5; J. O. Dimmock, in Semiconductors and Semimetals, edited by R. K. Willardson and A. C. Beer (Academic, New York, 1967), p.259.»
Subnatural linewidth averaging for coupled atomic and cavity-mode oscillators. H. J. Carmichael, R. J. Brecha, M. G. Raizen, H. J. Kimble and P. R. Rice in Phys. Rev. A 40:5516 (1989).
On the interaction between the radiation field and ionic crystals. K. Huang in Proc. R. Soc. Lond. A 208:352 (1951).
Theory of the Contribution of Excitons to the Complex Dielectric Constant of Crystals. J. J. Hopfield in Phys. Rev. 112:1555 (1958).
Polariton Reflectance and Photoluminescence in High-Purity GaAs. D. Sell, S. Stokowski, R. Dingle and J. DiLorenzo in Phys. Rev. B 7:4568 (1973).
Raman Scattering by Polaritons. C. Henry and J. Hopfield in Phys. Rev. Lett. 15:964 (1965).
Resonant Brillouin Scattering of Excitonic Polaritons in Gallium Arsenide. R. G. Ulbrich and C. Weisbuch in Phys. Rev. Lett. 38:865 (1977).
«See, e.g., M. Born and E. Wolf, Principles of Optics (Pergamon, Oxford, 1986), 6th ed.»
«See, e.g., Vertical-cavity surface-emitting lasers: Design, growth, fabrication, characterization. J. Jewell, J. Harbison, A. Scherer, Y. Lee and L. Florez in IEEE Quantum Electron. 27:1332 (1991)., and references therein.»
«The transition from 2D excitons to 3D polaritons was recently discussed by »Optical dynamics in crystal slabs: Crossover from superradiant excitons to bulk polaritons. J. Knoester in Phys. Rev. Lett. 68:654 (1992).
Room-temperature excitonic nonlinear-optical effects in semiconductor quantum-well structures. D. Chemla and D. Miller in J. Opt. Soc. Am. B 2:1155 (1985).
«See, e.g., Subpicosecond four-wave mixing in GaAs$x$Ga$_{1-x}$As quantum wells. K. Leo, E. Göbel, T. Damen, J. Shah, S. Schmitt-Rink, W. Schäfer, J. Müller, K. Köhler and P. Ganser in Phys. Rev. B 44:5726 (1991)., and references therein.»
Accurate theory of excitons in GaAs-Ga$_{1-x}$Al$_x$As quantum wells. L. C. Andreani and A. Pasquarello in Phys. Rev. B 42:8928 (1990).
«See, e.g. , C. Weisbuch and B. Vinter, Quantum Semiconductor Heterostructures (Academic, Boston, 1991).»

I'm also interested in papers he didn't quote, but could or should have:

The dispersion of excitons, polaritons and biexcitons in direct-gap semiconductors. B. Hönerlage, R. Lévy, J. B. Grun, C. Klingshirn and K. Bohnert in Phys. Rep. 124:161 (1985).

See also those he couldn't quote as they came up later, but are related to this no-cavity polaritons and how various types (surface, waveguides, etc.) relate to each others (or making specific comments about this).