Multiphoton multifocal microscopy (MMM) usually has been achieved through a combination of galvo scanners with microlens arrays, with rotating disks of microlens arrays, and cascaded beam splitters with asynchronous rastering of scanning mirrors. Here we describe the achievement of a neat and compact MMM by use of a high-diffraction-efficiency diffractive-optic element that generates a multiple-spot grid of uniform intensity to achieve higher fidelity in imaging of live cells at adequate speeds.
We review the most important fabrication techniques for glass and plastic refractive microlenses and we quantitatively characterize in a systematic way the corresponding state-of-the-art microlenses, which we obtained from selected research groups. For all our measurements we rely on three optical instruments: a non-contact optical profiler, a transmission Mach-Zehnder interferometer and a Twyman-Green interferometer. To conclude, we survey and discuss the different fabrication techniques by comparing the geometrical and optical characteristics of the microlenses, the range of materials in which the lenses can be produced, their potential for low-cost fabrication through mass-replication techniques and their suitability for monolithic integration with other micro-optical components.
In this paper we report on successful supercontinuum generation extending from the near to the mid-infrared region in the range 700-2500 nm in a micro-structured fiber made of lead-bismuth-galate glass and pumped in the femtosecond regime with a wavelength of 1540 nm. The flatness of 5 dB is observed in most of the registered spectrum 1000 -2500 nm. The improved spectral and thermo-physical properties of this custom made lead-bismuth-galate glass against tellurite and commercially available heavy oxide SF-57 glasses are presented.
We present a novel fabrication technology for nano-structured graded index micro-optical components, based on the stack-and-draw method used for photonic crystal fibres. These discrete structures can be described with an effective refractive index distribution. Furthermore we present spherical nano-structured microlenses with a flat facet fabricated with this method and designed using an algorithm based on the Maxwell-Garnett mixing formula. Finally we show theoretical verification by using FDTD simulations for a nano-structured lens as well as experimental data obtained in the microwave regime.
We report on octave-spanning supercontinuum generation under pumping with 1360 nm, 120 fs pulses, in an all-solid, all-normal dispersion photonic crystal fiber. The fiber was drawn from thermally matched oxide soft glasses with a hexagonal lattice 35 µm in diameter, 2.5 µm solid core and pitch of Λ/d = 0.9. The fiber was designed for normal dispersion broadly flattened in the 1200–2800 nm range. Experimentally recorded supercontinuum spectrum covered a 900–1900 nm bandwidth and was reconstructed with good agreement using numerical modeling. To the best of our knowledge, this is the first report of an experimentally demonstrated octave-spanning supercontinuum bandwidth, reaching as far as 1900 nm in the all-normal dispersion regime.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.