J. Phys. III France
Volume 4, Numéro 12, December 1994
Page(s) 2361 - 2370
DOI: 10.1051/jp3:1994282
J. Phys. III France 4 (1994) 2361-2370

Etched arrays of quantum well optical bistable microresonators

J. L. Oudar1, T. Rivera1, R. Kuszelewicz1 and F. Ladan2

1  France TELECOM, CNET-Paris B, Laboratoire de Bagneux, B.P. 107, 92225 Bagneux Cedex, France
2  CNRS - Laboratoire de Microstructures et de Microélectronique, B.P. 107, 92225 Bagneux Cedex, France

(Received 9 February 1994, accepted 12 July 1994)

We report the operation of etched GaAs/AlGaAs multiple quantum well microresonators as low threshold all-optical bistable devices. The studied samples are 2-dimensional arrays of cylindrical microresonators of $6~\mu$m height, with diameters of $4~\mu$m and $6.4~\mu$m. They are realized by SiCl 4 reactive ion etching of an epitaxial high finesse vertical microcavity structure. Due to the lateral carrier and light confinement, optical bistability is observed with a strongly reduced threshold power, below 100 $~\mu$W for the $4~\mu$m diameter devices. The optical confinement allows to achieve a high cavity Q factor in a reduced volume, and leads to the observation of multiple hysteresis loops due to the transverse mode structure of $6.4~\mu$m diameter microresonators. The low bistability threshold, obtained without post-etching surface treatment, is attributed to a selfpassivation occurring during the etching process, as evidenced by the observation of a thin coating film protecting the microresonator vertical surfaces.

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