Fiber optic photoluminescence sensor

A photoluminescence sensor comprising in combination:

• a source of light having an output;
• an optical waveguide having proximal and distal ends and having a photoluminescent material at said distal end;
• means for collecting a photoluminescent light;
• a reflecting microscope objective for directing said source light into said optical waveguide to cause said photoluminescent material to transmit said photluminescent light back into said optical waveguide and for focusing said photoluminescent light from said optical waveguide;
• means for detecting said photoluminescent light;
• a filter for preventing scattered exciting light from entering said detecting means;
• a chopper, disposed at the output end of said objective, for modulating said source light at a select frequency;
• and
• a lock-in amplifier tuned to measure an output from the detector means at said select frequency.

A photoluminescence sensor comprising in combination:

• a source of light;
• an optical waveguide having proximal and distal ends and having a photoluminescent material at said distal end for providing photoluminescent light;
• means for collecting said photoluminescent light;
• an objective for directing said source light into the proximal end of said optical waveguide;
• an objective for receiving said photoluminescent light and for focusing said photoluminescent light onto said means for collecting;
• a liquid filter for substantially only passing said photoluminescent light;
• a detector for detecting said photoluminescent light from said filter;
• a chopper disposed at the output of said objective for modulating said source light at a select frequency;
• and
• a lock-in amplifier tuned to measure the detector output at said select frequency.

A photoluminescence sensor comprising in combination:

• a source of light;
• an optical waveguide having proximal and distal ends and having a photoluminescent material at said distal end;
• means for collecting a photoluminescent light coming from said optical waveguide;
• an objective for directing said source light into said proximal end of said optical waveguide to cause said photoluminescent material to emit said photoluminescent light;
• an objective for receiving photoluminescent light from said waveguide and for focusing said photoluminescent light onto said means for collecting;
• a liquid filter for substantially only passing said photoluminescent light reflected from said collecting means;
• a detector for detecting said photoluminescent light from said filter;
• a chopper, located between said objectives and said waveguide, for modulating said light at a select frequency;
• and
• a lock-in amplifier tuned to measure an output from said detector at said select frequency.

A photoluminescence sensor comprising:

• a laser source of light;
• a concave mirror having at least one perforation for passing said source light through said at least one perforation;
• an optical waveguide having distal and proximal ends and having a photoluminescent material at said distal end;
• a Schwarzchild type reflecting microscope objective for directing said source light into said optical waveguide, and for receiving photoluminescent light emitted by said waveguide and for focusing said photoluminescent light onto said concave mirror;
• a detector for detecting said photoluminescent light reflected from said concave mirror;
• a liquid filter for preventing scattered light from entering said detector;
• a chopper, disposed at the source light output of said reflecting microscope, for modulating said source light at a select frequency;
• and
• a lock-in amplifier tuned to measure an output from said detector at said select frequency.