An optical-fiber-based probe for photonic crystal microcavities

作者：Srinivasan K^*; Barclay PE; Borselli M; Painter OJ

来源：IEEE Journal on Selected Areas in Communications, 2005, 23(7): 1321-1329.

DOI：10.1109/JSAC.2005.0851212

• microcavity
• photonic crystals (PCs)
• quantum optics

We review a novel method for characterizing both the spectral and spatial properties of resonant cavities within two-dimensional photonic crystals (PCs). An optical fiber taper serves as an external waveguide probe whose micron-scale field is used to source and couple light from the cavity modes, which appear as resonant features in the taper's wavelength-dependent transmission spectrum when it is placed within the cavity's near field. Studying the linewidth and depth of these resonances as a function of the taper's position with respect to the resonator produces quantitative measurements of the quality factor (Q) and modal volume (V-eff) of the resonant cavity modes. Polarization information about the cavity modes can be obtained by studying their depths of coupling when the cavity is probed along different axes by the taper. This fiber-based technique has been used to measure Q similar to 40,000 and V-eff similar to 0.9 cubic wavelengths in a graded square lattice PC microcavity fabricated in silicon. The speed and versatility of this fiber-based probe is highlighted, and a discussion of its applicability to other wavelength-scale resonant elements is given.

• 出版日期2005-7