GaN Photonic Crystal Nanocavity

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GaN Photonic Crystal Nanocavity
In this research, GaN-based photonic-crystal
nanocavities are fabricated and characterized.
The photonic crystals are formed by etching
regular, 2-dimensional periodic arrays of holes
into a thin membrane of GaN-material. In the
center of the array, some holes are left out of
the matrix to form the cavity. The structure
provides 3-dimensions of optical confinement,
leading to very high theoretical quality factors
(gt 10,000) of the cavity. The size of the pore,
periodicity of the array, and configuration of
missing holes determines the particular colors of
light that the cavity can emit. This effect has
been measured and compared favorably with theory.
The high quality factor of the cavity enables
the formation of very efficient blue lasers or
single photon sources in the GaN-based material
system. To date, Q factors of 800 have been
measured in this material system. Process
improvements will increase this number
significantly, as in the GaAs material system.
E. Hu (UCSB) Work performed at UCSB