title: Continuous-wave circular polarization terahertz imaging.
abstract: Biomedical applications of terahertz (THz) radiation are appealing because THz radiation is nonionizing and has the demonstrated ability to detect intrinsic contrasts between cancerous and normal tissue. A linear polarization-sensitive detection technique for tumor margin delineation has already been demonstrated; however, utilization of a circular polarization-sensitive detection technique has yet to be explored at THz frequencies. A reflective, continuous-wave THz imaging system capable of illuminating a target sample at 584 GHz with either linearly or circularly polarized radiation, and capable of collecting both cross- and copolarized signals remitted from the target, is implemented. To demonstrate the system’s utility, a fresh ex vivo human skin tissue specimen containing nonmelanoma skin cancer was imaged. Both polarization-sensitive detection techniques showed contrast between tumor and normal skin tissue, although some differences in images were observed between the two techniques. Our results indicate that further investigation is required to explain the contrast mechanism, as well as to quantify the specificity and sensitivity of the circular polarization-sensitive detection technique.
authors.affiliation: University of Massachusetts Lowell, Department of Physics and Applied Physics, 136 Olney Science Center, 1 University Avenue, Lowell, Massachusetts 01854, United StatesbBiomedical Terahertz Technology Center, 175 Cabot Street, Suite 114, Lowell, Massachus.
authors.forename: Jillian P
authors.initials: JP
authors.lastname: Martin
authors.affiliation: University of Massachusetts Lowell, Department of Physics and Applied Physics, 136 Olney Science Center, 1 University Avenue, Lowell, Massachusetts 01854, United StatesbBiomedical Terahertz Technology Center, 175 Cabot Street, Suite 114, Lowell, Massachus.
authors.forename: Cecil S
authors.initials: CS
authors.lastname: Joseph
authors.affiliation: University of Massachusetts Lowell, Department of Physics and Applied Physics, 136 Olney Science Center, 1 University Avenue, Lowell, Massachusetts 01854, United StatesbBiomedical Terahertz Technology Center, 175 Cabot Street, Suite 114, Lowell, Massachus.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Giles
mesh_terms: D003952:Diagnostic Imaging / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000000981:diagnostic imaging*; D055069:Terahertz Imaging; D055053:Terahertz Radiation