Optical fiber probe for monitoring fluid medium

• US 5,581,648 A
• Filed: 05/12/1994
• Issued: 12/03/1996
• Est. Priority Date: 03/05/1993
• Status: Expired due to Term

• Current Assignee: Armen N. Sahagen
• Original Assignee: Armen N. Sahagen
• Inventors: Sahagen, Armen N.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US08/241,499
• Time in Patent Office: 936 Days
• Field of Search: 385/125, 385/901, 385/902, 385/123, 385/12, 385/141, 385/142, 385/143, 385/144, 385/145
• US Class Current: 385/125
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 9/0055 bonded on a diaphragm
• CPC Class Codes: G01N 2021/0314 Double pass, autocollimated path
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: G01N 21/8507 Probe photometers, i.e. with optical measuring part dipped into fluid sample
• CPC Class Codes: G01N 2201/08 Optical fibres; light guides
• CPC Class Codes: G02B 6/3624 Fibre head, e.g. fibre probe termination optical details of light guide terminations G02B6/241; reshaping of light guides G02B6/2552; optical details of coupling light into or out of fibre end G02B6/262

Abstract

A probe for monitoring a fluid medium employing at least one fiber optic emitting a wave into the fluid medium. The fluid medium scatters or causes luminescence of the emitted wave which is then collected by at least one fiber optic. The probe includes a base having a hole and a window covering the hole of the base, wherein the window transmits electromagnetic waves. The probe collects scattered and luminescence of waves through one or more fiber optics placed behind the window and transmits the waves to a spectrometer connected to a computer which can analyze the fluid medium on a real-time on-line basis. Piezoresistive and temperature sensing elements are deposited on the window which can also serve as a force collector diaphragm. The elements are located primarily on the periphery of the diaphragm leaving a part of the diaphragm open for transmission and collection of the waves.

Claims

1. A fiber optic, comprising:

a fiber optic tube functioning as a cladding and having a first and second ends;

a fluid core in the fiber optic tube; and

a first window for sealing off the first end and/or a second window for sealing off the second end of the tube;

wherein either the first or the second window, or both are bandpass filters; and

wherein at least one window includes a surface having a shape selected from the group consisting of a truncated cone, a sphere, a sphere surrounded by a cone shaped annulus, a cone, and a concave cone periphery or any combination of shapes thereof.

2. The fiber optic of claim 1, wherein the tube is a material selected from the group consisting of crystalline refractory, amorphous refractory, metal, metal oxides, semiconductor material, an intermetallic, a plastic or a combination thereof.

3. The fiber optic of claim 1, wherein the tube is a material selected from the group consisting of diamond, sapphire, quartz, glass, plastic or a combination thereof having a refractive index less than that of the fluid core.

4. The fiber optic of claim 1, wherein the window is a material selected from the group consisting of diamond, sapphire, quartz, glass, plastic, intermetallics, amphorphous and crystalline semiconductor material, or a combination thereof capable of transmitting electromagnetic waves.

5. A plurality of fiber optics for emitting and/or collecting electromagnetic radiation, comprising:

a plurality of fiber optic tubes functioning as claddings and having a first and second ends;

a fluid core in a fiber optic tube; and

a first window for sealing off the first end and/or second window for sealing off the second end of a tube, wherein at least one window is shaped to increase electromagnetic radiation collection efficiency;

wherein at least one window includes a first and/or second major surface having a shape selected from group consisting of truncated cone, a sphere, a sphere surrounded by a cone shaped annulus, a cone, and a concave cone periphery or any combination of shapes thereof.

6. The fiber optic of claim 5, wherein the tubes are of a material selected from the group consisting of crystalline refractory, amorphous refractory, metal, metal oxides, semiconductor material, an intermetallic, a plastic or a combination thereof.

7. The fiber optic of claim 5, wherein the tubes are of a material selected from the group consisting of diamond, sapphire, quartz, glass, plastic or a combination thereof having a refractive index less than that of the fluid core.