Optical Fibers Functionalized with Photonic Crystal Resonant Optical Structures

Abstract

A photonic crystal (PC) device including one or more resonant optical structures defined by the photonic crystal structure is affixed to the end face of an optical fiber. The PC device is fabricated on a separate substrate, and then affixed to the fiber end face. This transfer can be facilitated by device templates which are laterally supported by tabs after an undercut etch. The tabs can be designed to break during transfer to the fiber, thereby facilitating transfer. Registration marks and / or the use of device templates having the same diameter as the fiber can be used to provide lateral alignment of the fiber to the resonant optical structures. Such alignment may be needed to provide optical coupling between the fiber and the resonant optical structures.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. provisional patent application 61 / 574,750, filed on Aug. 8, 2011, entitled “Optical Fibers Functionalized with Photonic Crystal Cavities”, and hereby incorporated by reference in its entirety.FIELD OF THE INVENTION[0002]This invention relates to fiber-coupled photonic crystal devices.BACKGROUND[0003]A photonic crystal (PC) has a periodic array of features (e.g., holes) in a background medium. Various devices can be fabricated by modifying the basic structure of a photonic crystal. For example, a PC cavity can be formed by a small cluster of missing holes in a PC lattice (effectively forming a point defect in the PC). As another example, a PC waveguide can be formed by a line of missing holes in a PC lattice.[0004]Photonic crystal devices can readily be fabricated on various semiconducting and / or dielectric substrates. However, it is often difficult to efficiently couple to the resulting PC devic...

AI Technical Summary

Benefits of technology

The present patent is about a device that can be attached to the end of an optical fiber. It contains structures that guide light and can be aligned to the fiber's core. This device can be made on a separate layer and attached to the fiber, using a transfer process. Alignment marks and device templates can be used to ensure accurate alignment. The technical effect of this invention is the attachment of a high-quality optical device to an optical fiber, allowing for better coupling of light and improved performance.

Problems solved by technology

This form factor is convenient for free space optical testing in the laboratory, but is difficult to integrate in larger systems having many devices.

Coupling light on- and off-chip is challenging due to severe size mismatch between PC components and external fiber optics.

Previous studies have shown the transfer of PC cavities onto rigid or flexible substrates, but, to our knowledge, none have demonstrated functional cavities coupled to the tip of an optical fiber.

A micromanipulator stage is used for positioning but we note that the precision required is low since the working fiber facet area is quite large.

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