Coupling system to a microsphere cavity

• US 20020018617A1
• Filed: 06/12/2001
• Published: 02/14/2002
• Est. Priority Date: 02/10/1999
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Yao, Steve, Maleki, Lute, Wu, Chi, Iltchenko, Vladimir
• Granted Patent: US 6,488,861 B2
• Time in Patent Office: Days
• US Class Current: 385/28
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 6/10 of the optical waveguide type G02B6/02, G02B6/24 take precedence; devices or arrangements for the control of light by electric, magnetic, electro-magnetic or acoustic means G02F1/00; transferring the modulation of modulated light G02F2/00; optical logic elements G02F3/00; optical analogue/digital converters G02F7/00
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/264 with optical elements between opposed fibre ends which perform a function other than beam splitting having lens focusing means G02B6/32; utilising prism or grating G02B6/34
• CPC Class Codes: G02B 6/29341 Loop resonators operating in a whispering gallery mode evanescently coupled to a light guide, e.g. sphere or disk or cylinder evanescent coupling for sensing fluorescence G01N21/648
• CPC Class Codes: H01S 3/0604 in the form of a plate or disc
• CPC Class Codes: H01S 3/083 Ring lasers fibre ring lasers H01S3/06791
• CPC Class Codes: H01S 5/1032 Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region
• CPC Class Codes: H01S 5/1075 Disk lasers with special modes, e.g. whispering gallery lasers

Abstract

A system of coupling optical energy in a waveguide mode, into a resonator that operates in a whispering gallery mode. A first part of the operation uses a fiber in its waveguide mode to couple information into a resonator e.g. a microsphere. The fiber is cleaved at an angle Φ which causes total internal reflection within the fiber. The energy in the fiber then forms an evanescent field and a microsphere is placed in the area of the evanescent field. If the microsphere resonance is resonant with energy in the fiber, then the information in the fiber is effectively transferred to the microsphere.

Claims

1. A method comprising:

forming a cylindrical cavity preform with vertical walls;

re-shaping said vertical walls in a way that removes a mode field from flat boundaries of the vertical walls;

treating the resulting shape to form an ellipsoidal geometry; and

rounding and smoothing edges of the ellipsoidal geometry to reduce radiation loss and to form a dielectric resonator body.

2. A method as in claim 1 wherein said cylindrical cavity preform has walls with a diameter of 100 to 200 μ

m, and a thickness of 20 to 40 μ

m.

3. A method as in claim 1 wherein said treatment comprises one of wet/dry etching, ion milling techniques, RTA laser treatment, ultraviolet treatment or infrared treatment.

4. A method as in claim 1 wherein said preform is formed of a silica material.

5. A resonator comprising a silica material formed to have at least one substantially elliptical cross-sectional area.