Scanning apparatus

Abstract

Methods and apparatus for directing radiation to and from a sample to be scanned. In one example, first radiation propagating along a first axis is reflected off of the first axis so as to impinge on the sample. In response to the first radiation, the sample emits second radiation, which is directed to a detector. In one aspect, the second radiation is received directly from the sample by a reflector, which reflects the second radiation such that it travels substantially through air to impinge on the detector. In another aspect, the second radiation is directed such that it travels toward the detector in a direction having a significant vector component parallel to the first axis. In yet another aspect, a detection surface of the detector is oriented essentially perpendicular to the first axis and adapted to detect at least some of the second radiation traveling in a direction non-parallel to the first axis.

1 . A method, comprising: 
 reflecting first radiation from a first surface, the first radiation provided along at least a portion of a first axis and reflected off of the first axis to impinge on a sample responsive to the first radiation; and    reflecting second radiation from a second surface, the second radiation emitted from the sample in response to the first radiation and reflected directly from the sample by the second surface such that the second radiation travels substantially through air.    
     
     
         2 . The method of  claim 1 , wherein the act of reflecting second radiation includes an act of reflecting second radiation from a second surface such that at least some reflected second radiation has a significant vector component in a direction parallel to the first axis.  
     
     
         3 . The method of  claim 1 , wherein the act of reflecting first radiation includes an act of reflecting first radiation from a first surface comprising at least one first reflective surface having a first normal and the act of reflecting second radiation includes an act of reflecting second radiation from a second surface comprising at least one second reflective surface having a second normal different from the first normal.  
     
     
         4 . The method of  claim 1 , wherein the act of reflecting first radiation includes an act of reflecting first radiation from the first surface such that the first radiation is reflected off the first axis onto a second axis along which the first radiation impinges on the sample.  
     
     
         5 . The method of  claim 1 , wherein the act of reflecting second radiation from a second surface causes at least some incident second radiation traveling in a first direction to travel in a second direction having a vector component perpendicular to the first axis that is opposite in sign to a respective vector component of the first direction.  
     
     
         6 . The method of  claim 1 , further comprising an act of detecting at least some of the second radiation reflected from the second surface.  
     
     
         7 . The method of  claim 6 , wherein the act of detecting includes an act of detecting at least some second radiation having a significant vector component parallel to the first axis.  
     
     
         8 . The method of  claim 6 , wherein the act of reflecting second radiation includes an act of reflecting second radiation from a second surface such that at least some of the second radiation has an incident direction and a reflected direction that are opposite in sign with respect to an axis perpendicular to the first axis and wherein the act of detecting includes an act of detecting at least some of the second radiation traveling in the reflected direction.  
     
     
         9 . The method of  claim 6 , wherein the act of detecting includes an act of detecting at least some second radiation traveling non-parallel to the first axis.  
     
     
         10 . The method of  claim 6 , wherein the act of detecting includes an act of detecting at least some second radiation traveling essentially parallel to the first axis.  
     
     
         11 . The method of  claim 6 , wherein the act of detecting second radiation includes an act of detecting at least some second radiation traveling in a reflected direction that has been substantially changed with respect to an axis perpendicular to the first axis from second radiation emitted from the sample traveling in an emitted direction.  
     
     
         12 . The method of  claim 1 , further comprising an act of providing a detector to detect at least some second radiation emitted from the sample.  
     
     
         13 . The method of  claim 12 , wherein the act of reflecting first radiation includes an act of reflecting first radiation traveling along at least a portion of the first axis in a direction away from the detector.  
     
     
         14 . The method of  claim 12 , wherein the act of reflecting first radiation includes an act of reflecting first radiation traveling along at least a portion of the first axis in a direction towards the detector.  
     
     
         15 . The method of  claim 12 , wherein the act of providing a detector includes an act of providing a detector oriented to facilitate detecting at least second radiation having a significant vector component parallel to the first axis.  
     
     
         16 . The method of  claim 12 , wherein the act providing a detector includes an act of providing a detector oriented to facilitate detecting second radiation traveling non-parallel to the first axis.  
     
     
         17 . The method of  claim 12 , wherein the act of providing a detector includes an act of providing a detector having a detection surface oriented essentially perpendicular to the first axis.  
     
     
         18 . The method of  claim 12 , wherein the act of providing a detector includes an act of providing a detector arranged such that the first axis passes substantially through the center of the detector.  
     
     
         19 . The method of  claim 12 , wherein the act of providing a detector includes an act of providing a detector arranged essentially symmetric about the first axis.  
     
     
         20 . The method of  claim 1 , wherein the act of reflecting first radiation includes rotating the first surface about the first axis.  
     
     
         21 . The method of  claim 20 , wherein the act of reflecting first radiation includes reflecting first radiation from the first surface such that it directly impinges on the sample.