4Pi spectral self-interference microscopy.
Spectral self-interference microscopy (SSM) relies on the balanced collection of light traveling two different paths from the sample to the detector, one direct and the other indirect from a reflecting substrate. The resulting spectral interference effects allow nanometer-scale axial localization of isolated emitters. To produce spectral fringes the difference between the two optical paths must be significant. Consequently, to ensure that both contributions are in focus, a low-numerical-aperture objective lens must be used, giving poor lateral resolution. Here this limitation is overcome using a 4Pi apparatus to produce the requisite two paths to the detector. The resulting instrument generalizes both SSM and 4Pi microscopy and allows a quantification of SSM resolution (rather than localization precision). Specifically, SSM is shown to be subject to the same resolution constraints as 4Pi microscopy.
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. bryn@uiuc.edu
Brynmor J
BJ
Davis
Mehmet
M
Dogan
Bennett B
BB
Goldberg
William C
WC
Karl
M Selim
MS
Unlü
Anna K
AK
Swan
D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D054023:Lasers, Semiconductor; D007909:Lenses; D008857:Microscopy, Interference / Q000295:instrumentation*; D012016:Reference Values; D012031:Refractometry / Q000295:instrumentation / Q000379:methods; D012680:Sensitivity and Specificity