Figure 2
From: Highly Efficient Coupling of Nanolight Emitters to a Ultra-Wide Tunable Nanofibre Cavity

Tuning of the fibre cavities.
(a), A schematic diagram and a picture of holder used for tensioning the fibre. (b), Normalized transmission spectra of an NFBC at different tunings. The distances the piezo actuator is moved are 0 μm, 57.5 μm, 160 μm, 270 μm, 176.7 μm, 70.8 μm and 0 μm for i-vii, respectively. (c), Reversible tuning of an NFBC. The behaviour of the resonance peak when the NFBC is tuned is shown. Black circles indicate stretching of the fibre while red diamonds indicate compressing.