Towards cavity optomechanics with integrated multi-element mechanical resonators
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Typ
Examensarbete för masterexamen
Program
Publicerad
2021
Författare
Kolvik, Johan
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Cavity optomechanics describes the interaction between an intracavity light field and a
mechanical resonator. This mutual coupling allows for a means to optically control mechanical
motion down to the quantum regime. Using an optomechanical device to observe
non-linear quantum effects, such as direct generation of non-classical states, requires the
strong single photon-phonon coupling regime, which is yet to be experimentally realized
for chip-based devices. Coupling light to the collective motion of an array of highly reflective
mechanical resonators has been predicted to increase the coupling strength and is
therefore a promising way forward in achieving this goal.
In this thesis, I present the first steps towards realizing cavity optomechanics with multielement
membrane-type resonators fabricated from an AlGaAs heterostructure. The optical
and mechanical properties of single- and double-layer resonators are characterized,
showing resonance frequencies in the 100 kHz regime and room temperature mechanical
quality factors of 104 at high vacuum. The reflectivity of the AlGaAs heterostructure is
measured to be > 95 % at telecom wavelengths. The membrane devices are subsequently
inserted as the back mirror of a 10 mm long Fabry-Pèrot-type cavity. This membrane-atthe-
edge geometry shows a cavity linewidth of 6.38(8) MHz, corresponding to a finesse of
2370(30). Finally, an experimental setup for characterizing optomechanical properties is
discussed, and its performance is analyzed in terms of cavity mirror impedance mismatch
and membrane clipping loss.
Beskrivning
Ämne/nyckelord
Cavity optomechanics , AlGaAs heterostructures , Micro-mechanical resonators , Optical measurement