Solid state cavity QED: Strong coupling in organic thin films

Publication Type:

Journal Article

Source:

Org. Electron., Elsevier, Volume 8, Issue 2–3, p.94-113 (2007)

ISBN:

1566-1199

Keywords:

2007, 2013 and earlier, Cyanine dye, Multilayer, optical properties, Polyelectrolytes, Semiconductor microcavity

Abstract:

We review our research efforts to develop solid state integrated devices that operate in the strong coupling limit of cavity quantum
electrodynamics (QED) for eventual application in high speed optical
switching, optical computing, and quantum computing. Our devices contain
J-aggregates of (organic) cyanine dyes which, by virtue of their molecular
arrangement and strong dipolar coupling, exhibit a collective narrow
linewidth high oscillator strength optical transition. Using J-aggregates,
the strong coupling limit can be reached at room temperature with large
coupling strengths (Rabi-splitting >250 meV) in exciton–polariton
microcavity structures. We demonstrate that high quality nanoscale thick
J-aggregate films can be uniformly deposited over macroscopic substrates,
engineered at the molecular level, and patterned into single or
multi-dimensional photonic bandgap structures. Our unique methods for
depositing J-aggregates enabled us to structure light emitting devices
that demonstrated the first ever electrically pumped polariton emission,
uniquely accomplished in room temperature operation. Additionally, we
demonstrated critically coupled resonators that concentrate nearly all of
the incident light into 5 nm thick J-aggregate films, yielding a record
high effective absorption constant of 6.8 × 106 cm−1 for films with
thickness that is less than 1% of the incident light wavelength. Such
remarkable optical properties, enabled by scalable deposition techniques,
suggest that J-aggregates are a unique materials platform on which to
demonstrate integrated exciton–polariton devices with the far reaching
properties of polaritons in the optical domain.