Double helix-PSF enables superresolution 3-D imaging

March 1, 2009
Researchers at Stanford University (Palo Alto, CA) and the University of Colorado at Boulder have demonstrated for the first time a method for 3-D optical imaging of objects smaller than 20 nm over a wide spatial range–overcoming the optical diffraction limit by an order of magnitude.

Researchers at Stanford University (Palo Alto, CA) and the University of Colorado at Boulder have demonstrated for the first time a method for 3-D optical imaging of objects smaller than 20 nm over a wide spatial range–overcoming the optical diffraction limit by an order of magnitude. Their approach uses single fluorescent molecules and a wide-field microscope. The researchers engineered the microscope’s point-spread function (PSF) to have two points of light in the image plane. Because the angle of the line between the spots changes depending on the axial position of the molecule, the PSF appears as a double-helix along the z axis of the microscope–which is why the researchers term it the double-helix PSF (DH-PSF).

Click here to enlarge image

The researchers report they are able to localize single fluorescent molecules within 10 to 20 nm over a large depth of field (2 µm) in a thick polymer sample. They accomplish this by finding the orientation and center of the two DH-PSF spots using a fluorophore. Repeated 500 ms acquisition of sparse subsets enable superresolution imaging of high concentrations of single molecules in all three dimensions. The technique holds promise for improving 3-D imaging even further, the researchers say, and is applicable to materials science as well as biological and biomedical studies. Contact Rafael Piestun at [email protected].

Sponsored Recommendations

Achromatic Lenses: High-Quality Custom Optics

March 13, 2025
Ensure clarity and accuracy in your optics systems with Lacroix’s achromatic lenses. Explore how our custom solutions minimize chromatic aberration for perfect results.

Manufacturing Considerations for Tolerancing Aspheres

March 13, 2025
Understand the critical factors in manufacturing aspheres and how Lacroix Optics ensures precise tolerancing in every optical component.

Explore Our Videos: Insights into Precision Optics

March 13, 2025
Get an inside look at Lacroix Optics with our collection of informative videos showcasing our capabilities, innovations, and processes.

Optical Assemblies: Reliable and Precise Solutions

March 13, 2025
Ensure your optical system works seamlessly with Lacroix Optics' custom optical assemblies. Discover the precision and reliability we bring to every project.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!