Giovanni Milione

Cylindrical vector beam generation from spun fiber

Recently there has been considerable interest in the generation of cylindrical vector beams for numerous possible applications in nano-biophotonics, optical imaging, the laser processing of materials and the generation of single photon sources among others. Cylindrical vector optical vortex beams are shown by propagating a fundamental laser mode through a spun ber. The polarization state of the output from the ber is characterized and the the process of this mode conversion will be discussed.

Orbital-Angular-Momentum Mode (De)Multiplexer: A Single Optical Element for MIMO-based and non-MIMO-based Multimode Fiber Systems

A mode (de)multiplexer in a basis of OAM modes for MIMO-based and non-MIMO-based multimode fiber systems is experimentally demonstrated which via a single optical element can (de)multiplex and generate individual modes with potential scalability.

Time-resolved fluorescence for breast cancer detection using an octreotate-indocyanine green derivative dye conjugate

Time-resolved fluorescence was used to investigate malignant and normal adjacent breast tissues stained with a conjugate of indocyanine green and octreotate. A marked increase in fluorescence lifetime intensity was seen in the breast cancer sample compared to the normal sample. The fluorescent lifetimes were also investigated and showed similar fluorescence decay curves in stained malignant and normal breast tissue. These results confirm that somatostatin receptors occur on human breast carcinomas, suggest that the presence of somatostatin receptors should be investigated as a marker of breast cancer aggressiveness, and suggest that this conjugate might be used to detect the presence of residual breast cancer after surgery, allowing better assessment of tumor margins and reducing the need for second or repeat biopsies in selected patients. These results may also provide clues for designing future treatment options for breast cancer patients.

Space division multiplexing in a basis of vector modes

We experimentally demonstrate space division multiplexing in a basis of vector modes. Vector modes are a modal bases set, which have spatially varying polarization. Our experimental realization operates with link capacity of 160 G-bit/s, modal crosstalk and BER results are presented.

Spatial principal states and vortex modes in optical fiber for communications

Using SU(N) group theory, we develop a formalism to superimpose N vortex modes and form N orthogonal principal states in fiber. These principal states provide a means to overcome the detrimental effects of mode coupling that occur in optical communications links. This formalism reduces to the Jones matrix eigenanalysis when N equals 2, which has been studied extensively to characterize polarization mode dispersion. Specifically we use the 4 vortex modes of the LP11 modal group to establish the principal states and we graphically display them using the higher order Poincare sphere, HOPS. For polarization mode dispersion and N = 2, we require 3 Pauli spin matrices and consequently 3 mux demux components to generate the Principal states. For N = 3, we use the 8 Gell Mann matrices and 8 components. For N = 4 as is the case for 4 the vortex modes of the LP11 modal group, we require 15 generators and 15 physical components, since these systems scale as N^2-1. The LP11 modal group includes the HE21 horizontal and vertical vortex modes as well as the transvers electric and transverse magnetic vortex modes. As an example, we describe in some detail a link with 3 and separately one with 4 principal states, which are superimposed from the vortex modes. We also show schematically the active and passive components required to multiplex and demultiplex the principal states.

Tuning vector vortex in spatially coherent supercontinuum multicolored optical beam using q-plate

Tuning vector vortex in spatially coherent multicolored beam is studied. A wavelength filter based on the tunable modal properties of light is experimentally demonstrated, and the polarization topology of optical beam profile is mapped. A hybrid mode-wavelength division multiplexing (HMWDM) scheme is proposed. In this scheme information is encoded in the wavelength of light, and the spatial mode and polarization modulation about the optical mode is used to turn on and off frequency channels. This scheme is applicable to increase information capacity of light and in high resolution microscopy.

Bandwidth analysis of the principal states superimposed from vortex modes propagating in an optical fiber

The wavelength dependence of the principal states of transmission in multimode fibers is analyzed using a group theoretical analysis. We expand our principal states analysis modes propagating in an optical fiber in a basis of optical vortices for super dense optical networks to include the wavelength width over which these states are valid. The theory is formulated using SU(N) group theory and eigen analysis to determine the modal expansion coefficients. To first order, the principal states are frequency and wavelength independent; however dependencies develop away from which the frequencies of the specific expansion coefficients are determined.

Using Hermite-Gaussian modes for free-space optical communication (Conference Presentation)

There is interest in using spatial modes of light to increase the data speed of free-space optical communication where, each spatial mode can be used as a state or channel with which to encode or carry data, respectively. Here, the use of Hermite-Gaussian modes for free-space optical communication is investigated. It is shown that due their symmetry with respect to lateral displacement, as compared to other spatial modes, such as, orbital angular momentum modes, a subset of Hermite-Gaussian modes can experience less mode-crosstalk and -dependent loss when laterally displaced at the data receiver.

Propagation and scattering of vector light beam in turbid scattering medium

Due to its high sensitivity to subtle alterations in medium morphology the vector light beams have recently gained much attention in the area of photonics. This leads to development of a new non-invasive optical technique for tissue diagnostics. Conceptual design of the particular experimental systems requires careful selection of various technical parameters, including beam structure, polarization, coherence, wavelength of incident optical radiation, as well as an estimation of how the spatial and temporal structural alterations in biological tissues can be distinguished by variations of these parameters. Therefore, an accurate realistic description of vector light beams propagation within tissue-like media is required. To simulate and mimic the propagation of vector light beams within the turbid scattering media the stochastic Monte Carlo (MC) technique has been used. In current report we present the developed MC model and the results of simulation of different vector light beams propagation in turbid tissue-like scattering media. The developed MC model takes into account the coherent properties of light, the influence of reflection and refraction at the medium boundary, helicity flip of vortexes and their mutual interference. Finally, similar to the concept of higher order Poincar´e sphere (HOPS), to link the spatial distribution of the intensity of the backscattered vector light beam and its state of polarization on the medium surface we introduced the color-coded HOPS.

Incoherent polarized white-light vecctor vortex from a q-plate

A spatially incoherent white light optical vortex is generated using a tunable liquid crystal q-plate and white lamp source. This work investigates the propagation of incoherent vector vortex to the far field, and makes comparisons with a coherent optical vortex at a particular wavelength. The contrast ratio between the vortex’s ring and core darkness is determined, and the polarization of the vortex s mapped. For the keywords, select up to 8 key terms for a search on your manuscripts subject.