title: Superresolved multiphoton microscopy with spatial frequency-modulated imaging.
abstract: Superresolved far-field microscopy has emerged as a powerful tool for investigating the structure of objects with resolution well below the diffraction limit of light. Nearly all superresolution imaging techniques reported to date rely on real energy states of fluorescent molecules to circumvent the diffraction limit, preventing superresolved imaging with contrast mechanisms that occur via virtual energy states, including harmonic generation (HG). We report a superresolution technique based on spatial frequency-modulated imaging (SPIFI) that permits superresolved nonlinear microscopy with any contrast mechanism and with single-pixel detection. We show multimodal superresolved images with two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) from biological and inorganic media. Multiphoton SPIFI (MP-SPIFI) provides spatial resolution up to 2η below the diffraction limit, where η is the highest power of the nonlinear intensity response. MP-SPIFI can be used to provide enhanced resolution in optically thin media and may provide a solution for superresolved imaging deep in scattering media.
authors.affiliation: Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523; Microscope Imaging Network Foundational Core Facility, Colorado State University, Fort Collins, CO 80523; Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO 80523; jjfield@rams.colostate.edu.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Field
authors.affiliation: Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523;
authors.forename: Keith A
authors.initials: KA
authors.lastname: Wernsing
authors.affiliation: Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523;
authors.forename: Scott R
authors.initials: SR
authors.lastname: Domingue
authors.affiliation: Department of Physics, Colorado School of Mines, Golden, CO 80401; National Renewable Energy Laboratory, Golden, CO 80401;
authors.forename: Alyssa M
authors.initials: AM
authors.lastname: Allende Motz
authors.affiliation: Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523; Microscope Imaging Network Foundational Core Facility, Colorado State University, Fort Collins, CO 80523; Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO 80523;
authors.forename: Keith F
authors.initials: KF
authors.lastname: DeLuca
authors.affiliation: National Renewable Energy Laboratory, Golden, CO 80401;
authors.forename: Dean H
authors.initials: DH
authors.lastname: Levi
authors.affiliation: Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523; Microscope Imaging Network Foundational Core Facility, Colorado State University, Fort Collins, CO 80523; Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO 80523;
authors.forename: Jennifer G
authors.initials: JG
authors.lastname: DeLuca
authors.affiliation: Department of Physics, Colorado School of Mines, Golden, CO 80401;
authors.forename: Michael D
authors.initials: MD
authors.lastname: Young
authors.affiliation: Department of Physics, Colorado School of Mines, Golden, CO 80401;
authors.forename: Jeff A
authors.initials: JA
authors.lastname: Squier
authors.affiliation: Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523; Microscope Imaging Network Foundational Core Facility, Colorado State University, Fort Collins, CO 80523; Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO 80523; School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523.
authors.forename: Randy A
authors.initials: RA
authors.lastname: Bartels
mesh_terms: D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D008962:Models, Theoretical
keywords: harmonic generation; multiphoton microscopy; superresolution