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Photoporation is a rapidly expanding technique for the introduction of macromolecules into single cells. However, there remains no study into the true efficiency of this procedure. Here, we present a detailed analysis of transfection efficiency and cell viability for femtosecond optical transfection using a titanium sapphire laser at 800 nm. Photoporation(More)
The introduction and subsequent expression of foreign DNA inside living mammalian cells (transfection) is achieved by photoporation with a violet diode laser. We direct a compact 405 nm laser diode source into an inverted optical microscope configuration and expose cells to 0.3 mW for 40 ms. The localized optical power density of ~1200 MW/m2 is six orders(More)
The authors present Raman cluster mapping of de-paraffinized normal cervical tissue and demonstrate the ability of this approach to differentiate between normal squamous epithelium and cervical intraepithelial neoplasia (CIN). Multivariate analysis was performed by hierarchical cluster analysis (HCA) of the Raman spectra associated with the different tissue(More)
Common-path optical coherence tomography (CPOCT) is known to reduce group velocity dispersion and polarization mismatch between the reference and the sample arm as both arms share the same physical path. Existing implementations of CPOCT typically require one to incorporate an additional cover glass within the beam path of the sample arm to provide a(More)
We describe a synchronously pumped femtosecond optical parametric oscillator based on periodically poled LiNbO(3) that is broadly tunable in the mid infrared. A transmission window of periodically poled lithium niobate beyond the conventionally accepted infrared absorption edge of 5.4 mum has been exploited to produce idler pulses that are tunable across a(More)
We perform a comparison of optical tweezing using continuous wave (cw) and femtosecond lasers. Measurement of the relative Q-values in the femtosecond and cw regimes shows that femtosecond optical tweezers are just as effective as cw optical tweezers. We also demonstrate simultaneous optical tweezing and in-situ control of two-photon fluorescence (at 400nm)(More)
We demonstrate, for the first time to our knowledge, femtosecond-regime mode locking of a Tm,Ho-codoped crystalline laser operating in the 2 microm spectral region. Transform-limited 570 fs pulses were generated at 2055 nm by a Tm,Ho:KY(WO(4))(2) laser that produced an average output power of 130 mW at a pulse repetition frequency of 118 MHz. Mode locking(More)
We demonstrate laser action in diode-pumped microchip monolithic cavity channel waveguides of Yb:KGd(WO(4))(2) and Yb:KY(WO(4))(2) that were fabricated by ultrafast laser writing. The maximum output power achieved was 18.6 mW with a threshold of approximately 100 mW from an Yb:KGd(WO(4))(2) waveguide laser operating at 1023 nm. The propagation losses for(More)
Propagation invariant light fields such as Bessel light beams are of interest in a variety of current areas such as micromanipulation of atoms and mesoscopic particles, laser plasmas, and the study of optical angular momentum. Considering the optical fields as a superposition of conical waves, we discuss how the coherence properties of light play a key role(More)