220 likes | 360 Views
D. L. McAuslan, D. Korystov, and J. J. Longdell Jack Dodd Centre for Photonics and Ultra-Cold Atoms, University of Otago, Dunedin, New Zealand. David McAuslan – QIP-REIDS2011. Coherent Spectroscopy of Rare-Earth-Ion Doped Whispering Gallery Mode Resonators. David McAuslan – QIP-REIDS2011.
E N D
D. L. McAuslan, D. Korystov, and J. J. Longdell Jack Dodd Centre for Photonics and Ultra-Cold Atoms, University of Otago, Dunedin, New Zealand. David McAuslan – QIP-REIDS2011 Coherent Spectroscopy of Rare-Earth-Ion Doped Whispering Gallery Mode Resonators David McAuslan – QIP-REIDS2011
Whispering Gallery Modes (WGMs). Strong Coupling Regime of Cavity QED. Experiments. Atom-Cavity Coupling. Coherence Time. Population Lifetime. Spectral Hole Lifetime. Optical Bistability/Normal-Mode Splitting. David McAuslan – QIP-REIDS2011 Outline David McAuslan – QIP-REIDS2011
Electric field confined to equator. High quality factor. Small mode volume. Ideal for strong coupling cavity QED. David McAuslan – QIP-REIDS2011 Whispering Gallery Modes [1] [1] S. Arnold et al., Opt. Lett. 28 (2003). David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Whispering Gallery Modes [1] [4] [3] [2] [2] [3] [1] T. J. Kippenberg, PhD. Thesis (2004). [2] A. Schliesser et al., Nature Physics 4 (2008). [3] Y. Park et al., Nano Lett. 6 (2006). [4] J. Hofer et al., PRA 82 (2010). David McAuslan – QIP-REIDS2011
κ – cavity decay rate: γ – atomic population decay rate: γh– atomic phase decay rate: g – coupling between atoms and cavity: David McAuslan – QIP-REIDS2011 Strong Coupling Regime David McAuslan – QIP-REIDS2011
Critical atom number: Saturation photon number: N0<1, n0<1. “Good cavity” strong coupling regime: g > κ, γ, γh. “Bad cavity” strong coupling regime: κ > g >> γ, γh. David McAuslan – QIP-REIDS2011 Strong Coupling Regime David McAuslan – QIP-REIDS2011
Reversible State Transfer Single Atom Detection David McAuslan – QIP-REIDS2011 Why Strong Coupling? D. L. McAuslan et al., Physical Review A 80, 062307 (2009) David McAuslan – QIP-REIDS2011
Measure the properties of a Pr3+:Y2SiO5 resonator. Atom-cavity coupling. Coherence time. Population lifetime. Spectral hole lifetime. Calculate cavity QED parameters to determine viability of strong-coupling regime. David McAuslan – QIP-REIDS2011 Aim of Experiments David McAuslan – QIP-REIDS2011
Resonator: 0.05% Pr3+:Y2SiO5. r = 1.95mm. Q = 2 x 106. Sample: 0.02% Pr3+:Y2SiO5. 5x5x5mm cube. David McAuslan – QIP-REIDS2011 Experimental Setup LO Probe D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 πPulse Length π = 0.32μs for Pin = 700μW D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
Rabi frequency: Atom-Cavity Coupling: Compare to g calculated from the theoretical mode volume (V = 5.40 x 10-13 m3 for r = 1.95mm): David McAuslan – QIP-REIDS2011 Atom-Cavity Coupling D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Coherence Time • Through Resonator • Coupled into Resonator e-2τ/T2 e-2τ/T2 D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Coherence Time • Through Resonator • Coupled into Resonator e-2τ/T2 e-2τ/T2 T2 = 30.8 μs T2 = 21.0 μs D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
Through Resonator Coupled into Resonator David McAuslan – QIP-REIDS2011 Population Lifetime e-Τ/T1 e-Τ/T1 D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
Through Resonator Coupled into Resonator David McAuslan – QIP-REIDS2011 Population Lifetime e-Τ/T1 e-Τ/T1 T1 = 205μs T1 = 187μs D. L. McAuslan et al., ArXiv:1104.4150 (2011) D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Spectral Hole Lifetime D. L. McAuslan et al., ArXiv:1104.4150 (2011) David McAuslan – QIP-REIDS2011
Optical bistability and normal-mode splitting studied by Ichimura and Goto in a Pr3+:Y2SiO5 Fabry-Perot resonator [1]. Theory modified for a WGM resonator. Fitting to experimental data gives: g = 2πx 2.2 kHz. David McAuslan – QIP-REIDS2011 Optical Bistability 800μW 400μW Sweep Sweep 200μW 100μW 80μW 40μW [1] K. Ichimura and H. Goto, PRA 74 (2006) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Cavity QED Parameters • This resonator: • κ = 2π x 138 MHz. • γ = 2π x 0.851 kHz. • γh= 2π x 2.34 kHz. • g = 2π x 1.73 kHz. • N0 = 2.15 x 105, n0 =0.166. • Need: • Smaller resonators. • Higher Q factors. • Different materials. David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Smaller V • Single point diamond turning. • Crystalline resonators with R = 40 μm. • Possible to reduce V by 3 orders of magnitude. [1] [1] I. S. Grudinin et al., Opt. Commun. 265 (2006) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Higher Q • We have measured Q = 2 x 108 in Y2SiO5 resonators. • Q = 3 x 1011 in CaF2 [1]. • Bulk losses in Y2SiO5 measured using Fabry-Perot cavity [2]. • α≤ 7 x 10-4 cm-1. • Max Q ~ 3 x 108. • At least 2 orders of magnitude improvement possible. • Bulk losses should be lower in IR. [1] A. A. Savchenkov et al., Opt Exp. 15 (2007) [2] H. Goto et al., Opt. Exp. 18 (2010) David McAuslan – QIP-REIDS2011
David McAuslan – QIP-REIDS2011 Materials • N0<1 for different materials. David McAuslan – QIP-REIDS2011
Performed an investigation into strong coupling cavity QED with rare-earth-ion doped WGM resonators. Direct measurement of cavity QED parameters of a Pr3+:Y2SiO5 WGM resonator. g = 2π x 1.73 kHz. γ= 2π x 0.851 kHz. γh= 2π x 2.34 kHz. Observed optical bistability and normal-mode splitting in resonator. Achieving the strong coupling regime of cavity QED is feasible based on existing resonator technology. David McAuslan – QIP-REIDS2011 Conclusions