Wavelength tunability of components based on the evanescent coupling from a side-polished fiber to a high-index-overlay waveguide.

A number of in-line components utilizing the evanescent coupling between a side-polished fiber and a high-index slab overlay have recently been demonstrated. The wavelength response of the structure shows a series of resonances, the position of which must be precisely controlled for practical applications. We present experimental and theoretical results for the tuning of the resonance position through variation of the superstrate parameters.