Sensing apparatus having an optical assembly that collimates emitted light for detection

Abstract

An apparatus for optical sensing of samples includes an optical source, an optical assembly, a sample holder, an objective lens, and a detector. The objective lens collimates light emitted by the sample. Preferably, the optical assembly rotates about an axis, allowing the sensing apparatus to sense results from plural locations on a sample without moving the sample. Moving the sample in a linear direction while rotating the optical assembly allows sensing of an entire sample. Preferably, light from the optical source enters the optical assembly along the axis of rotation. Sensing methods consistent with the invention are also described.

1 - 20 . (canceled) 
   
   
       21 . A sensing apparatus comprising:
 a sample holder configured to receive a sample;   an optical source configured to emit excitation light;   an optical assembly configured to direct the excitation light to the sample, the optical assembly being spaced from the sample holder and being rotatable in a full circle about an axis; and   a detector configured to receive light emitted by the sample, wherein the excitation light is directed to the sample while the optical assembly rotates through at least one of a first arc and a second arc.   
   
   
       22 . The sensing apparatus of  claim 21 , wherein the excitation light is directed to the sample only while the optical assembly rotates through the first arc. 
   
   
       23 . The sensing apparatus of  claim 21 , wherein the first arc is a leading arc, the second arc is a trailing arc, and the leading arc and the trailing arc occupy substantially opposite sides of the circle. 
   
   
       24 . The sensing apparatus of  claim 23 , wherein the sample is configured to move such that a location on the sample moves past the leading arc before moving past the trailing arc. 
   
   
       25 . The sensing apparatus of  claim 24 , wherein the excitation light is directed to the sample only while the optical assembly rotates through the leading arc. 
   
   
       26 . The sensing apparatus of  claim 24 , wherein the excitation light is directed to the sample only while the optical assembly rotates through the trailing arc. 
   
   
       27 . The sensing apparatus of  claim 21 , wherein the optical source is a first optical source, the excitation light is first excitation light, and the sensing apparatus further comprises a second optical source outputting second excitation light. 
   
   
       28 . The sensing apparatus of  claim 27 , wherein
 the first excitation light is directed to the sample while the optical assembly rotates through the first arc,   the second excitation light is prevented from reaching the sample while the optical assembly rotates through the first arc,   the second excitation light is directed to the sample while the optical assembly rotates through the second arc, and   the first excitation light is prevented from reaching the sample while the optical assembly rotates through the second arc.   
   
   
       29 . The sensing apparatus of  claim 21 , further comprising an optical chopper configured to prevent the excitation light from reaching the sample while the optical assembly rotates through the second arc. 
   
   
       30 . The sensing apparatus of  claim 29 , wherein
 the first arc is a leading arc,   the second arc is a trailing arc,   the leading arc and the trailing arc occupy substantially opposite sides of the circle, and   the sample is configured to move such that a location on the sample moves past the leading arc before moving past the trailing arc.   
   
   
       31 . The sensing apparatus of  claim 29 , wherein
 the optical source is a first optical source and the excitation light is first excitation light,   the sensing apparatus further comprises a second optical source outputting second excitation light, and   the optical chopper is configured to prevent the first excitation light from reaching the sample while the optical assembly rotates through the second arc and to prevent the second excitation light from reaching the sample while the optical assembly rotates through the first arc.   
   
   
       32 . The sensing apparatus of  claim 21 , further comprising a blocking filter configured to prevent the excitation light from reaching the sample while the optical assembly rotates through the second arc. 
   
   
       33 . The sensing apparatus of  claim 32 , wherein
 the first arc is a leading arc,   the second arc is a trailing arc,   the leading arc and the trailing arc occupy substantially opposite sides of the circle, and   the sample is configured to move such that a location on the sample moves past the leading arc before moving past the trailing arc.   
   
   
       34 . The sensing apparatus of  claim 32 , wherein
 the optical source is a first optical source and the excitation light is first excitation light,   the sensing apparatus further comprises a second optical source outputting second excitation light, and   the blocking filter is configured to prevent the first excitation light from reaching the sample while the optical assembly rotates through the second arc.   
   
   
       35 . The sensing apparatus of  claim 34 , wherein the blocking filter is a first blocking filter, further comprising a second blocking filter configured to prevent the second excitation light from reaching the sample while the optical assembly rotates through the first arc. 
   
   
       36 . The sensing apparatus of  claim 21 , further comprising a control circuit configured to allow the excitation light to reach the sample while the optical assembly rotates through the first arc. 
   
   
       37 . The sensing apparatus of  claim 36 , wherein
 the first arc is a leading arc,   the second arc is a trailing arc,   the leading arc and the trailing arc occupy substantially opposite sides of the circle, and   the sample is configured to move such that a location on the sample moves past the leading arc before moving past the trailing arc.   
   
   
       38 . The sensing apparatus of  claim 36 , wherein
 the optical source is a first optical source and the excitation light is first excitation light,   the sensing apparatus further comprises a second optical source outputting second excitation light, and   the control circuit is configured to prevent the first excitation light from reaching the sample while the optical assembly rotates through the second arc and to prevent the second excitation light from reaching the sample while the optical assembly rotates through the first arc.   
   
   
       39 . A method of using a sensing apparatus, comprising the steps of:
 providing excitation light from an optical source;   rotating an optical assembly in a circle around an axis;   directing the excitation light to a sample while an optical assembly rotates through at least one of a first arc and a second arc; and   detecting light emitted by the sample.   
   
   
       40 . The method of  claim 39 , wherein
 the first arc is a leading arc, the second arc is a trailing arc, and the leading arc and the trailing arc occupy substantially opposite sides of the circle, the method further comprising the steps of   moving the sample such that a location on the sample moves past the leading arc before moving past the trailing arc; and   directing the excitation light to the sample only while the optical assembly rotates through the leading arc.   
   
   
       41 . The method of  claim 40 , wherein the excitation light is first excitation light, further comprising the step of directing second excitation light to the sample while the optical assembly rotates through the trailing arc. 
   
   
       42 . The method of  claim 41 , further comprising the steps of:
 preventing the first excitation light from reaching the sample while the optical assembly rotates through the trailing arc; and   preventing the second excitation light from reaching the sample while the optical assembly rotates through the leading arc.