title: A mirrorless spinwave resonator.
abstract: Optical resonance is central to a wide range of optical devices and techniques. In an optical cavity, the round-trip length and mirror reflectivity can be chosen to optimize the circulating optical power, linewidth, and free-spectral range (FSR) for a given application. In this paper we show how an atomic spinwave system, with no physical mirrors, can behave in a manner that is analogous to an optical cavity. We demonstrate this similarity by characterising the build-up and decay of the resonance in the time domain, and measuring the effective optical linewidth and FSR in the frequency domain. Our spinwave is generated in a 20 cm long Rb gas cell, yet it facilitates an effective FSR of 83 kHz, which would require a round-trip path of 3.6 km in a free-space optical cavity. Furthermore, the spinwave coupling is controllable enabling dynamic tuning of the effective cavity parameters.
authors.affiliation: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Pinel
authors.affiliation: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Jesse L
authors.initials: JL
authors.lastname: Everett
authors.affiliation: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Hosseini
authors.affiliation: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Geoff T
authors.initials: GT
authors.lastname: Campbell
authors.affiliation: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Ben C
authors.initials: BC
authors.lastname: Buchler
authors.affiliation: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Ping Koy
authors.initials: PK
authors.lastname: Lam