Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 4: II-VI semiconductors
HL 4.1: Vortrag
Montag, 23. März 2009, 10:15–10:30, POT 51
Monolithic distributed Bragg reflectors and microcavities lattice matched to ZnTe — •Wojciech Pacuski1,2, Carsten Kruse1, Stephan Figge1, Tomasz Jakubczyk2, Andrzej Golnik2, Jan Gaj2, and Detlef Hommel1 — 1Institute of Solid State Physics, University of Bremen, Postfach 330 440, D-28334 Bremen, Germany — 2Institute of Experimental Physics, University of Warsaw, Hoza 69, PL-00-681 Warszawa, Poland
A distributed Bragg reflector (DBR) is a high quality mirror based on alternating layers with high and low refractive index. In a monolithic DBR made of semiconductors both layers should have the same lattice parameter, what makes the design and fabrication of such structures quite challenging. For the first time we present a monolithic distributed Bragg reflector with lattice parameter matched to ZnTe. It can be deposited on a ZnTe substrate with high crystalline quality.
Our DBRs were grown using molecular beam epitaxy (MBE) on a 1μm thick fully relaxed ZnTe buffer layer deposited on GaAs substrate. New materials presented in our work allow us to reach a high refractive index step Δn = 0.5. It results in a broad spectral stopband exceeding 60 nm width and in reflectivity coefficient as high as 99% (for only 15 DBR pairs). We are motivated by applications (e.g. lasers, detectors) for the orange and red spectral range; therefore our structures are designed for wavelengths close to 650 nm. In order to confirm the suitability of the structures for device applications, we realized a microcavity, which consists of a λ cavity sandwiched between two DBRs. It has a Q value exceeding 500.