US 5,901,261 A · Fiber optic interface for optical probes with enhanced photonic efficiency, light manipulation, and stray light rejection

Abstract

Fiber optic interfaces that can readily reject the collection of stray light while efficiently collecting desired light that has interacted with the subject media. These fiber optic interfaces may be incorporated into optical probes and probe tips for enhanced photonic efficiency, light manipulation, and stray light rejection. These probes are particularly well suited for use in instrumentation including spectral analysis and the light-scattering branches of spectroscopy. Specifically, the optical probes exhibit benefits for spectral analyses including those referred to as Raman, fluorescence, Rayleigh, luminescence, and diffuse reflectance. A typical probe includes a center emitter fiber surrounded by collection fibers. These fibers are arranged into a bundle and positioned behind a window. The end faces of the emitter fiber and the collection fibers are shaped to form an optical interface with desired optical characteristics. The outer and inner faces of the window may also be shaped to enhance the desired characteristics of the optical interface. In one configuration, the window's outer face is formed into a convex face so that specular reflections arising from the window's outer face are directed back toward the emitter. In another configuration, the fiber assembly is encapsulated in a low refractive index window. The window's inner face is in intimate contact with the fiber end face. In this configuration, the low refractive index encapsulent facilitates light manipulation while providing protection, isolation, and other benefits.

Claims49

Dependent claims

An optical interface for a fiber optic device, comprising:

an emitter fiber defining an end face and a longitudinal axis, the emitter fiber operable for emitting light defining an illumination zone;
a window having an inner face positioned proximate to the end face of the emitter fiber, and an outer face longitudinally spaced from the inner face;
the end face of the emitter fiber progressively slopes away from the outer face of the window with increased radial offset from the longitudinal axis of the emitter fiber;
a collection device positioned proximate to the end face of the emitter fiber;
and
the end face of the emitter fiber shaped to substantially prevent normally-propagating light emerging from the end face of the emitter fiber and reflecting off the outer face of the window from collection by the collection device.

3 more elements

An interface for a fiber optic device, comprising:

an emitter fiber defining an end face and a longitudinal axis;
a collector fiber substantially parallel to the emitter fiber and defining an end face that is adjacent to the end face of the emitter fiber, the collector fiber operable for collecting light within a reception zone;
and
the end face of the emitter fiber shaped to substantially prevent normally-propagating light emerging from the end face of the emitter fiber and reflecting off a surface that is proximate to the end face of the emitter fiber from entering the end face of the collector fiber.

1 more element

A method for designing an optical interface for a fiber optic device including an emitter fiber defining an end face and a longitudinal axis, the emitter fiber operable for emitting light defining an illumination zone, and a collector fiber substantially parallel to the emitter fiber and defining an end face that is adjacent to the end face of the emitter fiber, the collector fiber operable for collecting light within a reception zone, comprising the steps of:

shaping the end face of the emitter fiber to substantially prevent normally-propagating light emerging from the end face of the emitter fiber and reflecting off a surface approximately the end face of the emitter fiber from entering the end face of the collector fiber;
and
shaping the end face of the collector fiber to direct the reception zone toward the illumination zone.

A machine for manufacturing an optical interface for a fiber optic device including an emitter fiber defining an end face and a longitudinal axis, the emitter fiber operable for emitting light defining an illumination zone, a collector fiber substantially parallel to the emitter fiber and defining an end face that is adjacent to the end face of the emitter fiber, the collector fiber operable for collecting light within a reception zone, and a window having an inner face positioned proximate to the end faces of the emitter and collector fibers, the window also having an outer face longitudinally spaced from the inner face, comprising:

means for shaping the profile of the end face of the emitter fiber to lie between a minimum angle profile and a maximum angle profile,
the minimum angle profile defined to approximate a profile that is,
minimized at its center point while directing the normally-propagating light emitted from the end face of the emitter fiber and reflecting off of the outer face of the window into the emitter fiber, and
progressively sloped with radial offset across the end face of the emitter fiber so that the slope remains minimized while directing the normally-propagating light emitted from the end face of the emitter fiber and reflecting off of the outer face of the window into the emitter fiber;
and
the maximum angle profile defined to approximate a profile that is,
maximized near its center point while directing the normally-propagating light emitted from the end face of the emitter fiber and reflecting off of the outer face of the window into the emitter fiber, and
progressively sloped with radial offset across the end face of the emitter fiber so that the slope remains maximized while directing the normally-propagating light emitted from the end face of the emitter fiber and reflecting off of the outer face of the window into the emitter fiber;
and
means for shaping the end face of the collector fiber to direct the reception zone toward the illumination zone.

7 more elements

a holding device restraining and spinning the emitter and collector fibers;
and
a shape imparting device configured to,
shape the end face of the emitter fiber to substantially prevent normally-propagating light emerging from the end face of the emitter fiber and reflecting off the outer face of the window from entering the end face of the collector fiber;
and
shape the end face of the collector fiber to direct the reception zone toward the illumination zone.

3 more elements

Dependencies are inferred from the claim text.

Fiber optic interface for optical probes with enhanced photonic efficiency, light manipulation, and stray light rejection

Life of this patent

Fiber optic interface for optical probes with enhanced photonic efficiency, light manipulation, and stray light rejection

Life of this patent

Abstract

Claims49